Title of Invention

"A COMPOUND OF FORMULA I"

Abstract A compound of Formula I, wherein: X is C; W is N with the proviso that when W is N, R2 does not exist; V is C; R1 is halogen; R3 is 1,2,3-triazolyl attached at position N-l; E is hydrogen or a pharmaceutically acceptable mono or bis salt thereof; Y is R10, R11, R12, R13, R14, R15, R16, R17 are each H; R18 is selected from the group consisting of C(O)-phenyl or quinazolyl.
Full Text The present invention relates to a compound of formula I.
This application claims the benefit of U.S. Provisional Application Serial Numbers 60/635,231 filed December 10, 2004 and 60/553,320 filed March 15, 2004.
FIELD OF THE INVENTION
This invention provides compounds having drug and bio-affecting properties, their pharmaceutical compositions and method of use. In particular, the invention is concerned with new prodrug derivatives with antiviral activity. More particularly, the present invention relates to compounds useful for the treatment of HIV and AIDS.
BACKGROUND ART
HIV-1 (human iminunodeficiency virus -1) infection remains a major medical problem, with an estimated 42 million people infected worldwide at the end of 2002. The number of cases of HIV and AIDS (acquired immunodeficiency syndrome) has risen rapidly. In 2002, ~5.0 million new infections were reported, and 3.1 million people died from AIDS. Currently available drugs for the treatment of HIV include ten nucleoside reverse transcriptase (RT) inhibitors or approved single pill combinations (zidovudine or AZT (or Retrovir®), didanosine (or Videx®), stavudine (or Zerit®), lamivudine (or 3TC or Epivir®), zalcitabine (or DDC or Hivid®), abacavir succinate (or Ziagen®), Tenofovir disoproxil fumarate salt (or Viread®), Combivir® (contains -3TC plus AZT), Trizivir® (contains abacavir, lamivudine, and zidovudine) and Emtriva® (emtricitabine); three non-nucleoside reverse transcriptase inhibitors: nevirapine (or Viramune®), delavirdine (or Rescriptor®) and efavirenz (or Sustiva®), nine peptidomimetic protease inhibitors or approved formulations: saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, lopinavir, Kaletra®(lopinavir and
Ritonavir), Atazanavir (Reyataz ), Fosamprenavir® and one fusion inhibitor which
targets viral gp41 T-20 (FUZEON ). Each of these drugs can only transiently
restrain viral replication if used alone. However, when used in combination, these
drugs have a profound effect on viremia and disease progression. In fact, significant
reductions in death rates among AIDS patients have been recently documented as a
consequence of the widespread application of combination therapy. However,
despite these impressive results, 30 to 50% of patients ultimately fail combination
drag therapies. Insufficient drug potency, non-compliance, restricted tissue
penetration and drug-specific limitations within certain cell types (e.g. most
nucleoside analogs cannot be phosphorylated in resting cells) may account for the
incomplete suppression of sensitive viruses. Furthermore, the high replication rate
and rapid turnover of HIV-l combined with the frequent incorporation of mutations,
leads to the appearance of drug-resistant variants and treatment failures when suboptimal
drug concentrations are present (Larder and Kemp; Gulick; Kuritzkes;
Morris-Jones et al\ Schinazi et al; Vacca and Condra; Flexner; Berkhout and Ren et
al; (Ref. 6-14)). Therefore, novel anti-HIV agents exhibiting distinct resistance
patterns, and favorable pharmacokinetic as well as safety profiles are needed to
provide more treatment options.
Currently marketed HIV-l drugs are dominated by either nucleoside reverse
transcriptase inhibitors or peptidomimetic protease inhibitors. Non-nucleoside
reverse transcriptase inhibitors (NNRTIs) have recently gained an increasingly
important role in the therapy of HIV infections (Pedersen & Pedersen, Ref 15). At
least 30 different classes of NNRTI have been described in the literature (De Clercq,
Ref. 16) and several NNRTIs have been evaluated in clinical trials.
Dipyridodiazepinone (nevirapine), benzoxazinone (efavirenz) and bis(heteroaryl)
piperazine derivatives (delavirdine) have been approved for clinical use. However,
the major drawback to the development and application of NNRTIs is the propensity
for rapid emergence of drug resistant strains, both in tissue cell culture and in treated
individuals, particularly those subject to monotherapy. As a consequence, there is
considerable interest in the identification of NNRTIs less prone to the development of
resistance (Pedersen & Pedersen, Ref 15). A recent overview of non-nucleoside
reverse transcriptase inhibitors: "Perspectives on novel therapeutic compounds and
strategies for the treatment of HIV infection", has appeared (Buckheit, reference 99).
A review covering both NRTI andNNRTIs has appeared (De Clercq, reference 100).
An overview of the current state of the HIV drugs has been published (De Clercq,
reference 101).
Several indole derivatives including indole-3-sulfones, piperazino indoles,
pyrazino indoles, and 5H-indolo[3,2-b][l,5]benzothiazepine derivatives have been
reported as HIV-1 reverse transciptase inhibitors (Greenlee et al, Ref. 1; Williams et
al, Ref. 2; Romero et al, Ref. 3; Font et al, Ref. 17; Romero et al, Ref. 18; Young et
al, Ref. 19; Genin et al, Ref. 20; Silvestri et al, Ref. 21). Indole 2-carboxamides have
also been described as inhibitors of cell adhesion and HIV infection (Boschelli et al,
US 5,424,329, Ref. 4). 3-Substituted indole natural products (Semicochliodinol A
and B, didemethylasterriquinone and isocochliodinol) were disclosed as inhibitors of
HIV-1 protease (Fredenhagen et al, Ref. 22).
Structurally related aza-indole amide derivatives have been disclosed
previously (Kato et al, Ref. 23(a); Levacher et al, Ref. 23(b); Dompe Spa, WO-
09504742, Ref. 5(a); SmitliKline BeechamPLC, WO-09611929, Ref. 5(b); Schering
Corp., US-05023265, Ref. 5(c)). However, these structures differ from those claimed
herein in that they are monoaza-indole mono-amide rather than oxoacetamide
derivatives, and there is no mention of the use of these compounds for treating viral
infections, particularly HIV.
New drugs for the treatment of HIV are needed for the treatment of patients
who become resistant to the currently approved drugs described above which target
reverse transcriptase or the protease. One approach to obtaining these drugs is to find
molecules which inhibit new and different targets of the virus. A general class of
inhibitors which are under active study are HIV entry inhibitors. This general
classification includes drugs aimed at several targets which include chemokine
receptor (CCR5 or CXCR4) inhibitors, fusion inhibitors targeting viral gp41, and
inhibitors which prevent attachment of the viral envelope, gp!20, the its human
cellular target CD4. A number of reviews or general papers on viral entry inhibitors
have recently appeared and some selected references are:
Chemokine receptor antagonists as HIV entiy inhibitors. Expert Opinion on
Therapeutic Patents (2004), 14(2), 251-255.
Inhibitors of the entry of HIV into host cells. Meanwell, Nicholas A.; Kadow, John F.
Current Opinion in Drug Discovery & Development (2003), 6(4), 451-461.
Virus entry as a target for anti-HIV intervention. Este, Jose A. Retrovirology
Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat
Autonoma de Barcelona, Badalona, Spain. Current Medicinal Chemistry (2003),
10(17), 1617-1632.
New antiretroviral agents. Rachline, A.; Joly, V. Service de Maladies Lxfectieuses et
Tropicales A, Hopital Bichat-Claude Bernard, Paris, Fr. Antibiotiques (2003),
5(2), 77-82.
New antiretroviral drugs. Gulick, R. M. Cornell HIV Clinical Trials Unit, Division
of International Medicine and Infectious Diseases, Weill Medical College of Cornell
University, New York, NY, USA. Clinical Microbiology and Infection (2003),
9(3), 186-193.
Sensitivity ofHIV-1 to entjy inhibitors correlates with envelope/coreceptor affinity,
receptor density, and fusion kinetics. Reeves, Jacqueline D.; Gallo, Stephen A.;
Ahmad, Navid; Miamidian, John L.; Harvey, Phoebe E.; Sharron, Matthew;
Pohlmann, Stefan; Sfakianos, Jeffrey N.; Derdeyn, Cynthia A.; Blumenthal, Robert;
Hunter, Eric; Doms, Robert W. Department of Microbiology, University of
Pennsylvania, Philadelphia, PA, USA. Proceedings of the National Academy of
Sciences of the United States of America (2002), 99(25), 16249-16254. CODEN:
PNASA6 ISSN: 0027-8424.
Opportunities and challenges in targeting HIV entry. Biscone, Mark J.; Pierson,
Theodore C.; Doms, Robert W. Department of Microbiology, University of
Pennsylvania, Philadelphia, PA, USA. Current Opinion in Pharmacology (2002),
2(5), 529-533.
HIV entiy inhibitors in clinical development. O'Hara, Bryan M.; Olson, William C.
Progenies Pharmaceuticals, Inc., Tarrytown, NY, USA. Current Opinion in
Pharmacology (2002), 2(5), 523-528.
Resistance mutation in HIV entiy inhibitors. Hanna, Sheri L.; Yang, Chunfu; Owen,
Sherry M.; Lai, Renu B. HIV Immunology and Diagnostics Branch, Division of
AIDS, STD, Atlanta, GA, USA. AIDS (London, United Kingdom) (2002),
16(12), 1603-1608.
HW entry: are all receptors created equal? Goldsmith, Mark A.; Doms, Robert W.
Genencor International, Inc., Palo Alto, CA, USA. Nature Immunology (2002),
3(8), 709-710. CODEN: NIAMCZ ISSN: 1529-2908.
Peptide and non-peptide HIV fusion inhibitors. Jiang, Shibo; Zhao, Qian; Debnath,
Asim K. The New York Blood Center, Lindsley F. Kimball Research Institute, New
York, NY, USA. Current Pharmaceutical Design (2002), 8(8), 563-580.
There are two general approaches for preventing the initial attachment of viral
membrane, gp!20, to cellular CD4 which are a) inhibitors which bind to human CD4
and block attachment of viral envelope (gp!20) and b) inhibitors which bind to viral
gp!20 and prevent the binding of cellular CD4. The second approach has the
advantage that it inhibits a viral target and, if selective, minimizes the chances of
perturbing nonnal human physiology or causing side effects. With this approach, in
order to overcome a spectrum in susceptability to drug caused by variability in the
sequences of viral envelope and to suppress the development of resistance, it is
important to achieve plasma levels of drug that is as many multiples as possible over
the EC50 or other measure of the concentration of drug needed to kill virus. As
discussed later, these inhibitors appear safe so to be of wide utility in man they,
therefore, must be able to achieve exposure levels sufficient to enable virus
suppression. The higher the multiple of drug levels over the level needed to inhibit
viral growth, the more efficiently and completely the suppresion of viral replication
and the lower the chance for viral mutation and subsequent development of resistance
to treatment. Thus, important aspects contributing to the efficacy of viral attachment
inhibitors include not only intrinsic potency and safety, but also pharmacokinetics and
pharmaceutical properties which allow attainment of high plasma exposure at a
physically feasible dose and an acceptable, preferably convenient, administration
schedule. This invention describes a prodrug approach which greatly enhances the
maximum exposure and the ability to increase exposure multiples (i.e., multiples of
drug exposure greater than ECso or ECgo) upon dose escalation of efficacious
members of a previously disclosed class of HIV attachment inhibitors.
A series of recent publications and disclosures characterize and describe a
compound labelled as BMS-806, an initial member of a class of viral entry inhibitors
which target viral gp-120 and prevent attachment of virus to host CD4.
A small molecule HIV-1 inhibitor that targets the HIV-1 envelope and inhibits CD4
receptor binding. Lin, Pin-Fang; Blair, Wade; Wang, Tao; Spicer, Timothy; Guo, Qi;
Zhou, Nannaii; Gong, Yi-Fei; Wang, H. -G. Heidi; Rose, Ronald; Yamanaka,
Gregory; Robinson, Brett; Li, Chang-Ben; Fridell, Robert; Deminie, Carol; Demers,
Gwendeline; Yang, Zheng; Zadjura, Lisa; Meanwell, Nicholas; Colonno, Richard.
Proceedings of the National Academy of Sciences of the United States of America
(2003), 100(19), 11013-11018.
Biochemical and genetic characterizations of a novel human immunodeficiency virus
type 1 inhibitor that blocfa gp!20-CD4 interactions. Guo, Qi; Ho, Hsu-Tso; Dicker,
Ira; Fan, Li; Zhou, Nannan; Friborg, Jacques; Wang, Tao; McAuliffe, Brian V.;
Wang, Hwei-gene Heidi; Rose, Ronald E.; Fang, Hua; Scarnati, Helen T.; Langley,
David R.; Meanwell, Nicholas A.; Abraham, Ralph; Colonno, Richard J.; Lin, Pinfang.
Journal of Virology (2003), 77(19), 10528-10536.
Method using small heterocyclic compounds for treating HIV infection by preventing
interaction ofCD4 andgp!20. Ho, Hsu-Tso; Dalterio, Richard A.; Guo, Qi; Lin,
Pin-Fang. PCT Int. Appl. (2003), WO 2003072028A2.
Discoveiyof4-benzoyl-l-[(4-methoxy-lH-pyrrolo[2,3-b]pyridin~3~yl)oxoacetyl]-2-
(R)-methylpiperazine (BMS-378806): A Novel HIV-1 Attachment Inhibitor That
Interferes with CD4-gpl20 Interactions. Wang, Tao; Zhang, Zhongxing; Wallace,
Owen B.; Deshpande, Milind; Fang, Haiquan; Yang, Zheng; Zadjura, LisaM.;
Tweedie, Donald L.; Huang, Stella; Zhao, Fang; Ranadive, Sunanda; Robinson, Brett
S.; Gong, Yi-Fei; Ricarrdi, Keith; Spicer, Timothy P.; Deminie, Carol; Rose, Ronald;
Wang, Hwei-Gene Heidi; Blair, Wade S.; Shi, Pei-Yong; Lin, Pin-fang; Colonno,
Richard 1; Meanwell, Nicholas A. Journal of Medicinal Chemistry (2003), 46(20),
4236-4239.
N-1 nitrogen
BMS-806
hadole, azaindole and other oxo amide containing derivatives from this class
have been disclosed in a number of different PCX and issued U.S. patent applications
(Reference 93-95, 106, 108, 109,110, 111, and 112) and these references directly
relate to the compounds in this patent application. None of the compounds in these
references of prior art contain a methyl dihydrogen phosphate (or salt or mono or di
ester of the phosphate group) group appended to the N-1 nitrogen and thus the
compounds of this current invention represent new compositions of matter. This
moiety dramatically increases the utility of the parent compounds by functioning as a
prodrug modification which dramatically increases the maximum systemic exposure
of the parent molecules in preclinical models of human exposure. We believe
nothing in the prior art references can be construed to disclose or suggest the novel
compounds of this invention and their use to inhibit HIV infection.
This invention describes prodrugs of specific indole and azaindole
ketopiperazine amides which are extremely effective at improving the oral utility of
the parent molecules as antiviral agents particular/ as anti HIV drugs. The parent
molecules are relatively insoluble, and suffer from dissolution-limited or solubility
limited absorption which means as the dose is increased above a maximum level, less
and less of the drug dissolves in time to be absorbed into the circulation and they are
instead passed through the body to be eliminated as waste. The improvements
offered by the prodrug are necessary, for they allow drug levels in the body to be
increased significantly, which provides greater efficacy vs HIV virus and in particular
vs less sensitive or more resistant strains. Prodrugs are especially important for this
class of drugs since the drugs target the envelope of the HIV virus, a target which
varies from strain to strain and thus in which maximum exposure multiples are
desired. Because with a prodrug, more of the drug will be absorbed and reach the
target, pill burden, cost to the patient and dosing intervals could be reduced. The
identification of prodrugs with these properties is difficult and neither
straightforward, nor is a clear path to successful prodrug design disclosed hi the
literature. There is no clear prior art teaching of which prodrug chemistry to employ
nor which will be most effective. The following discussion and data will show that
the prodrugs described in this invention work surprisingly well. They release parent
drug extremely quickly and efficiently and enhance the exposure to levels which are
higher than reported for many prodrugs.
The use of prodrug strategies or methodologies to markedly enhance
properties of a drug or to overcome an inherent deficiency in the pharmaceutic or
pharmacokinetic properties of a drug can be used in certain circumstances to
markedly enhance the utility of a drug. Prodrugs differ from formulations in that
chemical modifications lead to an entirely new chemical entity which upon
administration to the patient, regenerates the parent molecule within the body. A
myriad of prodrug strategies exist which provide choices in modulating the
conditions for regeneration of the parent drug, the physical, pharmaceutic, or
pharmacokinetic properties of the prodrug, and the functionality to which the prodrug
modifications may be attached. However, none of these publications teach what
approach to use that result in the specific prodrugs herein invented. A number of
reviews or discussions on prodrug strategies have been published and a
nonexliaustive list is provided below:
Hydrolysis in Drug and pro drug Metabolism. Richard Testa and Joachim Mayer,
2003 Wiley-VCH publisher, ISBN 3-906390-25-x.
Design. ofProdrugs, Bundgard, H. Editor, Elsevier, Amsterdam, 1985.
Pharmacokinetics of drug targeting: specific implications for targeting viaprodrugs.
Stella, V. J.; Kearney, A. S. Dep. Plaarm. Chem., Univ. Kansas, Lawrence, KS,
USA. Handbook of Experimental Pharmacology (1991), 100(Targeted Drug
Delivery), 71-103. CODEN: HEPHD2 ISSN: 0171-2004. Journal; General Review
written in English. CAN 116:158649 AN 1992:158649 CAPLUS (Copyright 2004
ACS on SciFinder (R)).
Prodrugs. Do they have advantages in clinical practice? Stella, V. J.; Charman, W.
N. A.; Naringrekar, V. H. Dep. Pharm. Chem., Univ. Kansas, Lawrence, KS,
USA. Drugs (1985), 29(5), 455-73. CODEN: DRUGAY ISSN: 0012-6667.
Journal; General Review written in English. CAN 103:115407 AN 1985:515407
CAPLUS (Copyright 2004 ACS on SciFinder (R)).
Trends inprodrug research. Stella, V. J.; Naringrekar, V. H.; Charman, W. N. A.
Dep. Pharm. Chem., Univ. Kansas, Lawrence, KS, USA. Pharmacy International
(1984), 5(11), 276-9. CODEN: PHINDQ ISSN: 0167-3157. Journal; General
Review written in English. CAN 102:72143 AN 1985:72143 CAPLUS (Copyright
2004 ACS on SciFinder (R)).
While some technologies are known to have specific applications, ie to
improve solubility or absorption for example, the development of prodrugs remains,
to a great extent, an empirical exercise. Thus a number of strategies or chemical
modifications must usually be surveyed and the resulting compounds evaluated in
biological models in order to ascertain and gauge the success of prodrug strategies.
A successful prodrug strategy requires that a chemically reactive site in a
molecule be modified via addition of the prodrug moiety and that later under the
desired conditions in the patients the prodrug moiety will unmask and release parent
drug. The prodrug molecule must have suitable stability in an acceptable dosage
form prior to dosing, hi addition, the release mechanism must allow the prodrug to
regenerate parent drug efficiently and with kinetics that provide therapeutic levels of
parent drug at the disease target, hi our molecules, the indole or azaindole nitrogen
represents an acceptable point of attachment for a prodrug moiety.
The suggestion that a phosphate group joined by an appropriate chemistry or
linker can enhance oral exposure of a parent drug is a concept known in the art.
However, as will be discussed below, it is unpredictable to know that if using a
phosphate group to create a prodrug will work with a given drug substance. The
phosphate group temporarily alters the physical properties of the drug and is, thus, a
prodrug which increases the aqueous solubility of the resulting molecule, until it is
cleaved by alkaline phosphatase in the body or other chemical reaction of a rationally
designed linker. For example, in the following reference, the authors conclude
phosphates may improve oral efficac)'. In this reference a phosphate derivative of an
alcohol group in a poorly water soluble, lipophilic drug displayed better oral
bioavailbility than two other prodrugs and appeared to offer an advantage over the
parent molecule which possesed low oral bioavailability.
Evaluation of a targeted prodrug strategy to enhance oral absorption of poorly
water-soluble compounds. Chan, O. Helen; Schmid, Heidi L.; Stilgenbauer, Linda
A.; Howson, William; Horwell, David C.; Stewart, Barbra H. Pharmaceutical
Research (1998), 15(7), 1012-1018.
Two very pertinent and recent papers have published which discuss the
difficulties of identifying phosphate prodrugs with significant advantages over the
parent molecule for oral use.
A paper entitled "Absorption Rate Limit Considerations for Oral Phosphate
Prodrugs" by Tycho Heimbach et. al. in Pharmaceutical Research 2003, Vol 20, No.
6 pages 848-856 states "The surprising inability to use phosphate prodrugs by the oral
route prompted a study in a system being used to screen drug candidates for
absorption potential." This paper also reviews the reasons many phosphate prodrugs
were unsuitable for oral use and discusses several potential rate limiting factors in the
drug absorption process. The paper also identifies the few successful applications.
The paper attempts to identify properties which may make some drugs suitable for
oral delivery as phosphate prodrugs but the message is clear that this is still an
empirical science. This is emphasized by the conclusions of a second paper by the
same authors entitled "Enzyme mediated precipitation of parent drugs from their
phosphate prodrugs" by Tycho Heimbach et. al in International Journal of
Pharmaceutics 2003, 261, 81-92. The authors state in the Abstract that many oral
phosphate prodrugs have failed to improve the rate or extent of absorption compared
to their insoluble parent drugs. Rapid parent drug generation via intestinal alkaline
phosphatase can result in supersaturated solutions, leading to parent drug
precipitation. This would limit utility of the oral phopshates. The conclusions of this
paper state (quoted) "hi summary, precipitation of parent drugs from phosphate
prodrugs can be enzyme mediated. Preciptitation of certain drugs can also be
observed for certain drugs in the Caco-2 model. Since induction times decrease and
nucleation times increase with high supersaturation ratios, parent drugs can
precipitate when targeted prodrugs concentration are much higher than than the
parent drug's solubility ie for parent drugs with high supersaturation ratios. The
extent to which a parent drug precipitates during conversion of the prodrug is
dependent on the prodrug to parent conversion rates, prodrug effect on the
precipitation of parent drug, and the solubilization of the parent drug." As can be
seen by the author's conclusion, the process is a complex one and is dependent on
many factors which are impossible to predict in advance such as supersaturation
ratios, rate of prodrug conversions in vivo, and ability of the intestinal milieu to
solubilize parent and prodrug mixtures.
The two references by Heimbach describe the clinical status of phosphate
prodrugs and discuss the many failures and few successful examples. One example
of a clinical failure and one example of a success are provided below:
Etoposide® is an anticancer drug which is administered either via iv or oral routes.
Etoposide phosphate prodrugs are used clinically, but these structures differ from the
derivatives of the current application as this prodrug contains a phosphate formed by
direct attachment to a phenol moiety of the parent drug. The main reasons for
preparing a phosphate prodrug of the drug etoposide were to improve intravenous use
via increased solubility and reduction of excipients. Although the phosphate prodrug
was evaluated orally both preclinically and clinically it is only used clinically for iv
administration.
Synthesis of etoposidephosphate, BMY-40481: a-water-soluble clinically active
prodrug of etoposide, Saulnier, Mark G.; Langley, David R.; Kadow, John F.;
Senter, Peter D.; Knipe, Jay O.; Tun, Min Min; Vyas, Dolatrai M.; Doyle, Terrence
W. Bristol-Myers Squibb Co., Wallingford, CT, USA. Bioorganic & Medicinal
Chemistry Letters (1994), 4(21), 2567-72 and references therein.
As can be seen from the following two references, the benefits of the
phosphate moiety for oral dosing were not clear.
Randomized comparison of etoposide pharmacokinetics after oral etoposide
phosphate and oral etoposide. De Jong, R. S.; Mulder, N. H.; Uges, D. R. A.; Kaul,
S.; Winograd, B.; Sleijfer, D.Th.; Groen, H. J. M.; Willemse, P. H. B.; van der Graaf,
W. T. A.; de Vries, E. G. E. Department of Medical Oncology, University Hospital
Groningen, Groningen, Neth. British Journal of Cancer (1997), 75(11), 1660-
1666. This paper compared parent and prodrug directly and concluded that oral
etoposide phosphate does not offer a clinically relevant benefit over oral etoposide.
Etoposide bio availability after oral administration of the prodrug etoposide
phosphate in cancer patients during a phase I study. Chabot, G. G.; Armand, J.-P.;
Terref, C.; De Form', M.; Abigerges, D.; Winograd, B.; Igwemezie, L.; Schacter, L.;
Kaul, S.; et al. Department Medicine, Gustave-Roussy Institute, Villejuif, Fr.
Journal of Clinical Oncology (1996), 14(7), 2020-2030.
This earlier paper found that compared with literature data, oral EP had a 19%
higher F value compared with oral E either at low or high doses. They concluded this
higher F in E from oral prodrug EP appears to be a pharmacological advantage that
could be of potential pharmacodynamic importance for this drug. However the
previously mentioned study which reached opposite conclusions was done later and it
appears that the direct comparision data was more valid. Thus adding a phosphate
group to improve solubility is not a guarantee of improved oral efficacy.
A phosphate prodrug of the HIV protease inhibitor Amprenavir was prepared
and is the active ingredient of what has now become an improved drug for oral use.
This is an example of a rare success from this approach. The phosphate is directly
attached to a hydroxy moiety and serves to enhance solubility. Fosamprenavir alone
or in combination with another protease inhibitor ritonavir, which serves to inhibit
Cytochrome P450 3 A4-mediated metabolic deactivation, allow patients to receive
fewer pills, smaller pills (due to the need for less excipients), and to employ a less
frequent dosing schedule. Clearly, the structure of Amprenavir is significantly
different than the molecules of the present invention and does not predict success
with other classes of drugs or phosphate linker chemistry. Two references on
Fosamprenavir are included below but most recent data can be found by searching a
database well known in the art such as IDDB (A commercial database called
Investigational Drugs Database produced by Current Drugs Ltd.).
,Ph
Fosamprenavir vertex Pharmaceuticals/GlaxoSmithKline. [Erratum to document
cited in CA138:130388]. Corbett, Amanda H.; Kashuba, Angela D. M. School of
Pharmacy, The University of North Carolina Hospitals, Chapel Hill, NC, USA.
Current Opinion in Investigational Drugs (PharmaPress Ltd.) (2002), 3(5), 824.
Fosamprenavir Vertex Pharmaceuticals/GlaxoSmithKline. Corbett, Amanda H.;
Kashuba, Angela D. M. School of Pharmacy, The University of North Carolina
Hospitals, Chapel Hill, NC, USA. Current Opinion in Investigational Drugs
(PharmaPress Ltd.) (2002), 3(3), 384-390.
Searching the literature for examples which can be found listed under
keywords "prodrugs of indoles" or "prodrugs of azaindoles" identify a number of
references that have been described. We are not aware of any references in which
azaindole prodrugs 1.1.

or mono or ester of the phosphate group) moiety attached to N-l.
Regarding indole phosphate prodrugs, the publication by Zhu et. al. describes
a study to find an effective phosphate prodrug of PD 154075. In this molecule, either
the direct indole phosphate or a methyl dihydrogen phosphate or salt prodrug of the
indole nitrogen were unsuitable prodrugs due to a slow rate of regenerating the parent
molecule. Thus the novel and complex linker depicted below was developed to
incorporate a solubilizing phosphate.
Phosphate prodrugs ofPD 154075. Zhu, Zhijian; Chen, Huai-Gu; Goel, Om P.;
Chan, O. Helen; Stilgenbauer, Linda A.; Stewart, Barbra H. Division of Warner-
Lambert Company, Chemical Development, Parke-Davis Pharmaceutical Research,
Ann Arbor, MI, USA. Bioorganic & Medicinal Chemistry Letters (2000), 10(10),
1121-1124.
Many of the references describe the design of prodrugs for purposes other
than overcoming dissolution-limited absorption. A number of the prodrugs are not
attached to the indole or azaindole nitrogen or are designed to release radical
intermediates rather than the parent drug. The prodrugs described in this art and their
properties do not provide obvious solutions for improving the properties of the parent
HIV attachment inhibitors.
It has now been found that new methyl dihydrogen phosphate produgs and
pharmaceutically acceptable salts of the general structure shown below are useful as
anti HIV agents with a new mechanism that is currently not employed by exisiting
drugs. The need for drugs with new mechanisms is great since patients are left with
no options if they become resistant to the current drug classes, hi addition, drugs
with new mechanisms can be used in combinations with known classes of inhibitors
to cover the emergence of resistance to these drugs since strains of resistant virus are
likely still susceptible to drugs with an alternative mechanism.
We have found that these prodrugs are more water soluble than the parent
molecules, and rapidly convert to the parents after oral dosing in rodents or in in vitro
assays with human enzymes or tissues, hi addition, in one oral dose escalation study,
a prodrug provided surprising enhancements in drug exposure (AUC) and maximum
concentration (Cmax) as the dose increased. These predictive studies suggest these
prodrugs should provide advantages in dogs and humans.
The parent compound IVa has been studied in human clinical trials. The
compound was dosed in healthy human volunteers. A graph of the exposure vs dose
is shown in Figure 1.
As can be seen, single doses of a capsule formulation (red triangles) ranged in
size from 200-2400mgs in 200mg increments. It is also readily apparent from the
oral AUCs, that increases in drug exposure increased much more slowly and less than
proportionally with dose. In fact the differences or increase in exposure above
SOOmgs is minimal. With the dose ratios of 1:2:4:6:9:12 for capsule treatment under
fasted condition, the ratios of mean Cmax and AUC values are 1:1.3:2.4:2.3:2.1:2.7
and 1:1.5:2.3:2.0:1.9:2.4, respectively. Between 200-800 mg dose range the increases
in systemic exposure is dose-related although less than dose-proportional, while such
exposure is dose independent above dose of 800 mg. This phenomenon indicates that
the absorption of Compound IVa with the capsule formulation used is saturable
under fasted conditions.
The dose proportionality in systemic exposure seems to be much better
presented under fed condition (high fat meal) as ratios of Cmax and AUC are 1.6 and
1.5, respectively, when the dose ratio is 1:2.3 (800 mg vs. 1800 mg). As can be seen
by comparing the single 200mg dose of a solution of IVa (dark red square) with that
of the 200mg capsule dose, exposure from the solution was higher. Dosing with a
solution increased Compound IVa exposure. The Cmax and AUC of the solution
were approximately 8- and 3-fold, respectively, of those of the capsule (200 mg).
The relative bioavailability (32%) of the capsule to the solution formulation suggests
absorption is dissolution rate-limited, suggesting a potential to enhance systemic
exposure by improving the formulation.
A high fat meal had a positive food-effect on the compound. The Cmax after
a fed treatment were approximately 2.6 and 4.6 fold for 800 and 1800 mg doses,
respectively, of those of the fast treatment. The AUCs after a fed treatment were
approximately 2.5 and 4.7 fold for 800 and 1800 mg doses, respectively, of those of
the fasted treatment. The relative bioavailability (fed vs. fasted) values were 293%
and 509% for 800 mg and 1800 mg doses, respectively. The median Tmax changed
from 1.25 or 2 (fasted) to 4 (fed) hours.
For the 800 mg capsule with food, the average plasma concentration is 1001
and 218 ng/mL at 8 and 12 hours post dose, respectively. The results supported a
q!2h or q8h dosing regimen for a targeted Cmin value of at least 200 ng/mL after
multiple doses. This value was selected based on preclinical data. A further
summary of some of this data presented as a bar graph is shown in the second bar
graph in Figure 2B.
MULTIPLE DOSE STUDY IN HEALTHY HUMANS
A placebo-controlled, ascending multiple-dose study to evaluate the safety,
tolerability and pharmacokinetics of Compound IVa in healthy human subjects was
carried out. Dosing was continued at 12h intervals for 14days. In summary, the
preliminary PK results indicated that, after single and multiple Q12H doses of
Compound IVa, the exposure is generally dose proportional over the dose ranges of
400 to 1200 mg and 400 to 800 mg with high fat meal and light meal, respectively,
the exposure seems to be dose independent above these dose levels with the different
meal types, the accumulation is low to moderate (up to ~1.5 fold), and that there is a
diurnal variation in the exposure in that exposure is higher after an evening dose than
that after a morning dose. Thus, the exposure was better when dosing was combined
with a high fat meal and exposure increases with dose were higher with a high fat
meal.
This is similar to the results obtained in the above single dose study.
MULTIPLE DOSE STUDY IN HIV PATIENTS
Based on the exposure data from the studies in normal volunteers, an efficacy
study was carried out in HIV patients. An inital disclosure of this data has been made
in a talk and published abstract. "Antiviral Activity, Safety, and Tolerability of a
Novel, Oral Small-Molecule fflV-1 Attachment Inhibitor, F/a, in HIV-1-Infected
Subjects" G. Hanna, J. Lalezari, J. Hellinger, D. Wohl, T. Masterson, W. Fiske, J.
Kadow, P-F. Lin, M. Giordano, R. Colonno, D. Grasela. Abstract J-32, 02/11/2004,
11th Conference on Retroviruses and Opportunistic Infections (CROI), San
Francisco, CA. The study design included HTV+ adults who were either antiretroviral
therapy naive or off antiretroviral therapy for > 16 weeks. Their CD4 counts were
required to be > 250 cells/mmS and plasma HIV-1 RNA needed to be in the range
5,000-500,000 c/mL. There were 15 subjects in each dose arm and the ratio of
patients receiving drug:placebo was 4:1.
The placebo-controlled, sequential study of IVa utilized an initial dose arm of
800 mg PO every!2h followed by a second dosing arm of 1800 mg PO administered
every 12h. It is important to note that drug was administered in a capsule and in
combination with a high fat meal to increase exposure and plasma levels. Study drug
was administered for 7 days and the morning of Day 8. Subjects were followed for
14 days.
Study Results (for 18 of the 24 Patients Receiving Drug IVa)
Day 8 Change in HIV RNA
Over 14days, log 10 c/mL
Maximal change in HIV RNA
Over 14days, loglO c/mL
Day 8 Change in CD4,
cells/mmS
Mean (SD)
Range
Mean (SD)
Range
Mean (SD)
Range
Compound IVa
-0.72(0.51)
+0.34 to -1.37
-1.00(0.50)
-0.32 to -1.60
106(151)
-214 to +272
Placebo
-0.02 (0.40)
+0.45 to -0.26
-0.30 (0.08)
-.22 to -0.38
6(57)
-35 to +47
Study Results (for 18 of the 24 Patients Receiving Drug IVa)
Maximal Change in
HIV RNA Over 14
days n (%)
>0.5 loglO c/mL
>1.01oglOc/mL
'>1.51oglOc/mL
Compound IVa
8(67%)
7 (58%)
3 (25%)
Placebo
1. As can be seen by the data for the SOOmg dosing level in combination with a
high fat meal, significant antiviral activity was observed. However, only 58% of
patients had 1.0 log drop in viral load. A more robust antiviral response was seen
with the ISOOmg dosing regimen with a high fat meal where the mean response was a
-.96 loglO drop in viral load. This data shows that this drug has significant antiviral
activity at doses of SOOmg and ISOOmg (and thus in between) every 12hours in
combination with a high fat meal and therefore it could play a significant role in
combination therapy. An updated summary of the results with BMS-043 in man can
be obtained by viewing the abstract or slides from the oral presentation: "Antiviral
Activity, Safety, and Tolerability of a Novel, Oral Small-Molecule HIV-1 Attachment
Inhibitor, BMS-488043, in HIV-1-Infected Subjects" G. Hanna, J. Lalezari, J.
Hellinger, D. Wohl, T. Masterson, W. Fiske, J. Kadow, P-F. Lin, M. Giordano, R.
Colonno, D. Grasela. Abstract J-32, 02/11/2004, 11th Conference on Retroviruses
and Opportunistic Infections (CROI), San Francisco, CA.
Unfortunately, it will be unfeasible to deliver this drug chronically over many
months involving administration of a total of 9 capsules of 200 mg each, twice a day
in combination with a high fat meal for obvious health reasons so a new formulation
will be needed which provides increased exposure from a lower dose and which
eliminates the need for a high fat meal.
Thus the clinical data shows that a method for improving the exposure of this
drug from lower doses and in the absence of a high fat meal is necessary.
Thus the initial data on the prodrugs of this invention surprisingly predicts
they will improve the exposure of molecules such as IVa and deliver the parent drugs
in concentrations that will allow the drugs to be used in the absence of high fat meals,
with lower capsule burden, and chronically as a component of antiretroviral therapy.
Initial data obtained from dosing solid capsules of either the prodrug lab
(lysine salt) or solid parent molecule (IVa) to dogs are summarized in the first bar
graph Figure 2 A of Figure 2. As can be seen, after dosing prodrug lab (mono lysine
salt) either in fasted or dogs fed a high fat meal, the exposure is surprisingly high
when compared to dosing parent molecule. Also, the effect of fed vs fasted state is
minimal if any for the prodrug yet has an obvious effect on the exposure after dosing
the solid parent molecule. Thus, surprisingly, the exposure of parent molecule after
dosing of prodrug, shows no dependence on a high fat meal which predicts for more
consistent exposure levels after dosing than those from parent molecule. The bar
graph in Figure 2B summarizes the previously discussed human data for parent
molecule IVa and shows the dependence of exposure for the molecule on the high fat
meal, the non proportional increases in exposure vs dose, and the better exposure
from dosing a solution rather than solid formulation. As discussed below, this shows
dissolution or absorption rate limited exposure which in preclinical models, appears
to be surprisingly improved via use of the phosphate prodrug. The use of phosphate
prodrugs also increased exposure in fasted dogs vs parent for two other prodrugs.
Details of these experiments are contained in the experimental section. In addition,
details from various studies in rats, dogs, and monkeys for two additional prodrug
examples and in rats for another two prodrugs demonstrate the surprising utility of
these prodrugs to increase exposure over that obtained parent moelcule at doses
which correlate to those likely to be of utility for the treatment and inhibition of HIV
viral replication.
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SUMMARY OF THE INVENTION
The present invention comprises compounds of Formula I, their
pharmaceutical fonnulations, and their use in patients suffering from or susceptible to
a virus such as HIV. The compounds of Formula I, which include nontoxic
pharaiaceutically acceptable salts thereof, have the formula and meaning as described
below.
The present invention comprises a compound of Formula I,
wherein: (Figure Removed)
X is C or N with the proviso that when X is N, R1 does not exist;
W is C or N with the proviso that when W is N, R2 does not exist;
V is C;
R1 is hydrogen, methoxy or halogen;
R2 is hydrogen;
R3 is methoxy or heteroaryl, each of which may be independently optionally
substituted with one substituent selected from G; wherein heteroaryl is triazolyl,
pyrazolyl or oxadiazolyl;
E is hydrogen or a pharmaceutically acceptable mono or bis salt thereof;
Y is selected from the group consisting of
(Figure Removed)R , R11, R12, R13, R14, R15, R16, R17 are each independently H or methyl, with the
proviso that not more than two of R10-R17 are methyl;
R18 is selected from the group consisting of C(O)-phenyl, C(O)-pyridinyl, pyridinyl,
pyrimidinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, napthyridinyl,
pthalazinyl, azabenzofuryl and azaindolyl, each of which may be independently
optionally substituted with from one to two members selected from the group
consisting of methyl, -amino, -NHMe, -NMe2, methoxy, hydroxymethyl and halogen;
D is selected from the group consisting ofcyano, S(O)2R24, halogen, C(0)NR21R22,
phenyl and heteroaryl; wherein said pheriyl or heteroaryl is independently optionally
substituted with one to three same or different halogens or from one to three same or
different substituents selected from G; wherein heteroaryl is selected from the group
consisting of pyridinyl and oxadiazolyl;
A is selected from the group consisting of phenyl, pjTidinyl, furyl, thienyl, isoxazolyl
and oxazolyl wherein said phenyl, pyridinyl, furyl, thienyl, isoxazolyl and oxazolyl
are independently optionally substituted with one to three same or different halogens
or from one to three same or different substituents selected from G;
G is selected from the group consisting of alkyl, alkenyl, phenyl, hydroxy,
methoxy, halogen, -NR23C(0)- alkyl, -NR24R25, -S(0)2NR24R25, COOR26 and
-CONR24R25; wherein said (C1-6)alkyl is optionally substituted with hydroxy,
dimethylamino or one to three same or different halogen;
R26 is selected from the group consisting of hydrogen and (Ci-6)alkyl;
R20, R21, R22, R23, R24, R25 are independently selected from the group consisting of
hydrogen, (C1.6)alkyl and -(CH2)nNR27R28;
n is 0-6; and
R27 and R28 are each independently H or methyl.
A more preferred embodiment are compounds above wherein:
X and W are each N;
or compounds above wherein:
X is C; and
Another preferred embodiment are compounds as described above wherein:
R18 is -C(0)-Ph; and
Yis
Another preferred embodiment are compounds as described above wherein:
R3 is methoxy or triazolyl; wherein said triazolyl is optionally substituted with one
substituent selected from G;
R10 - R17 are each H; and
G is methyl.
Another preferred embodiment are compounds as described above wherein:
R1 is F, and R3 is 1,2,3-triazolyl attached at position N-l.
Another preferred embodiment are compounds as described above wherein:
R1 is OMe, and R3 is 3-methyl-1,2,4-triazolyl attached at position N-l.
Another preferred embodiment are compounds as described above wherein:
R1 and R3 are each methoxy.
Another preferred embodiment are compounds as described above wherein
the salt is sodium, lysine or tromethamine.
Another preferred embodiment of the invention is a pharmaceutical
composition which comprises an antiviral effective amount of a compound of
Formula I, including pharmaceutically acceptable salts thereof, and one or more
pharmaceutically acceptable carriers, excipients or diluents.
Another preferred embodiment is the pharmaceutical composition from
above, useful for treating infection by HIV, which additionally comprises an antiviral
effective amount of an AIDS treatment agent selected from the group consisting of:
(a) an AIDS antiviral agent;
(b) an anti-infective agent;
(c) an immunomodulator; and
(d) HIV entry inhibitors.
Also encompassed by the embodiments is a method for treating a mammal
infected with the HIV virus comprising administering to said mammal an antiviral
effective amount of a compound of Formula I, including pharmaceutically
accceptable salts thereof, and one or more pharmaceutically acceptable carriers,
excipients or diluents.
Another embodiment is method described above, comprising administering to
said mammal an antiviral effective amount of a compound of Formula I, including
pharmaceutically accceptable salts thereof, in combination with an antiviral effective
amount of an AIDS treatment agent selected from the group consisting of an AIDS
antiviral agent; an anti-infective agent; an immunomodulator; and an HIV entry
inhibitor.
Another embodiment is the intermediate compounds of Formula II, useful in
making compounds I,
(Figure Removed)
wherein:
X is C or N with the proviso that when X is N, R1 does not exist;
W is C or N with the proviso that when W is N, R2 does not exist;
VisC;
R1 is hydrogen, methoxy or halogen;
R2 is hydrogen;
R3 is methoxy or heteroaryl, each of which may be independently optionally
substituted with one substituent selected from G; wherein heteroaryl is triazolyl,
pyrazolyl or oxadiazolyl;
L and M are independently selected from the group consisting of hydrogen,
Ci-Ce alkyl, phenyl, benzyl, trialkylsilyl, -2,2,2-trichloroethoxy and 2-
trimethylsilylethoxy with the proviso that not more than one of L and M can be
hydrogen;
Y is selected from the group consisting of
(Figure Removed)
R10, R11, R12, R13, R14, R15, R16, R17 are each independently H or methyl, with the
proviso that not more than two of R10-R17 are methyl;
R18 is selected from the group consisting of C(0)-phenyl, C(O)-pyridinyl, pyridinyl,
pyrimidinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, naptliyridinyl,
pthalazinyl, azabenzofuryl and azaindolyl, each of which may be independently
optionally substituted with from one to two members selected from the group
consisting of methyl, -amino, -NHMe, -NMea, methoxy, hydroxymethyl and halogen;
D is selected from the group consisting of cyano, S(0)2R24, halogen, C(0)NR21R22,
phenyl and heteroaryl; wherein said phenyl or heteroaryl is independently optionally
substituted with one to three same or different halogens or from one to three same or
different substituents selected from G; wherein heteroaryl is selected from the group
consisting of pyridinyl and oxadiazolyl;
A is selected from the group consisting of phenyl, pyridinyl, furyl, tliienyl, isoxazolyl
and oxazolyl wherein said phenyl, pyridinyl, furyl., thienyl, isoxazolyl and oxazolyl
are independently optionally substituted with one to three same or different halogens
or from one to three same or different substituents selected from G;
I
G is selected from the group consisting of (C1-6alkyl, (C1-6)allcenyl, phenyl, hydroxy,
methoxy, halogen, -NR23C(0)-(C1-6)alkyl, -NR24R25, -S(O)2NR24R25, COOR26 and
-CONR24R25; wherein said (C1-6)alkyl is optionally substituted with hydroxy,
dimethylamino or one to three same or different halogen;
n (• R is selected from the group consisting of hydrogen and (Ci_6)alkyl;
R20, R21, R22, R23, R24, R25 are independently selected from the group consisting of
hydrogen, (C1-6)alkyl and -(CH2)nNR27R28;
R27 and R28 are each independently H or methyl; and
n is 0-6.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 illustrates AUC (Area Under the Curve) Versus Dosage in Human
Clinical Trials for Compound IVa.
Figure 2 illustrates AUC for Compound IVa and Prodrug lab Under Fasting
and Fed Conditions in Dog and Human Studies
Figure 3 illustrates IVc Oral AUC in Rats versus Dose Plots
Figure 4 illustrates IVc Oral Cmax in Rats versus Dose Plots
Figure 5 illustrates Plasma Profiles of We in Rats After Oral Dosing of Ic
Figure 6 illustrates Comparison of IVa Cmax and AUC in Male Rats Given
Either IVa or lab
Figure 7 illustrates Comparison of IVa Cmax and AUC in Dogs Given Either
IVa or lab
Figure 8 illustrates Hydrolysis of lab in Human Placental ALP Solutions and
the Formation of IVa
Figure 9 illustrates Plasma Concentration Versus Time Profiles of lab and IVa
Following IV and Oral Administration of lab in Rats and from the Historical Data of
F/a in Rats
Figure 10 illustrates Plasma Concentration Versus Time Profiles of lab and
PVa Following IV and Oral Administration of lab in Dogs and from the Historical
Data of IVa in Dogs
Figure 11 illustrates Plasma Concentration Versus Time Profiles of lab and
IVa Following IV and Oral Administration of lab in Monkeys and from the Historical
Data of IVa in Monkeys
Figure 12 illustrates Comparison of IVb Cmax and AUC in Male Rats Given
Either IVb or Ibb
Figure 13 illustrates Comparison of IVb Cmax and AUC in Dogs Given
Either IVb or Ibb
Figure 14 illustrates Hydrolysis of Ibb in Human Placental ALP Solutions and
the Formation of PVb
Figure 15 illustrates Plasma Concentration Versus Time Profiles of Ibb and
IVb Following IV and Oral Administration of Ibb in the Rat and the Historical Data
of IVb in the Rat
Figure 16 illustrates Plasma Concentration Versus Time Profiles of Ibb and
IVb Following IV and Oral Administration of Ibb in the Dog and the Historical Data
of rVb in the Dog
Figure 17 illustrates Plasma Concentration Versus Time Profiles of Ibb and
IVb Following IV and Oral Administration of Ibb in the Monkey and the Historical
Data of IVb in the Monkey
Figure 18 illustrates Comparison of IVc Cmax and AUC in Male Rats Given
Either IVc or Icb
Figure 19 illustrates Comparison of IVc Cmax and AUC in Dogs Given Either
IVc or Icb
Figure 20 illustrates Hydrolysis of Icb in Human Placental ALP Solutions and
the Formation of IVc
Figure 21 illustrates Plasma Concentration Versus Time Profiles of Icb and
IVc Following IV and Oral Administration of Icb in the Rat and the Historical Data
of IVc in the Rat
Figure 22 illustrates Plasma Concentration Versus Time Profiles of Icb and
We Following IV and Oral Administration of Icb in the Dog and the Historical Data
ofrVc in the Dog
Figure 23 illustrates Plasma Concentration Versus Time Profiles of Icb and
IVc Following IV and Oral Administration of Icb in the Monkey and the Historical
Data of IVc in the Monkey
DETAILED DESCRIPTION OF THE INVENTION
Since the compounds of the present invention, may possess asymmetric
centers and therefore occur as mixtures of diastereomers and enantiomers, the present
invention includes the individual diastereoisomeric and enantiomeric forms of the
compounds of Formula I in addition to the mixtures thereof.
DEFINITIONS
The term "Cj.g allcyl" as used herein and in the claims (unless specified
otherwise) mean straight or branched chain allcyl groups such as methyl, ethyl,
propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, hexyl and the like.
"Halogen" refers to chlorine, bromine, iodine or fluorine.
An "aryl" group refers to an all carbon monocyclic or fused-ring polycyclic
(i.e., rings which share adjacent pairs of carbon atoms) groups having a completely
conjugated pi-electron system. Examples, without limitation, of aryl groups are
phenyl, napthalenyl and anthracenyl. The aryl group may be substituted or
unsubstituted. When substituted the substituted group(s) is preferably one or more
selected from alkyl, cycloaUcyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy,
aryloxy, heteroaryloxy, heteroalicycloxy, thiohydroxy, thioaryloxy, thioheteroaryloxy,
thioheteroalicycloxy, cyano, halogen, nitro, carbonyl, O-carbamyl, N-carbamyl,
C-amido, N-amido, C-carboxy, 0-carboxy, sulfinyl, sulfonyl, sulfonamido,
trilialomethyl, ureido, amino and -NRxRy, wherein RxandRy are independently
selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, carbonyl,
C-carboxy, sulfonyl, trihalomethyl, and, combined, a five- or six-member
heteroalicyclic ring.
As used herein, a "heteroaryl" group refers to a monocyclic or fused ring (i.e.,
rings which share an adjacent pair of atoms) group having in the ring(s) one or more
atoms selected from the group consisting of nitrogen, oxygen and sulfur and, in
addition, having a completely conjugated pi-electron system. Unless otherwise
the hp.tp.rnarv! ornim mavhp. nttflchp.rl at either a narhrm nr nitrnpp.n atom
within the heteroaryl group. It should be noted that the term heteroaryl is intended to
encompass an N-oxide of the parent heteroaryl if such an N-oxide is chemically
feasible as is known in the art. Examples, without limitation, of heteroaryl groups are
furyl, thienyl, benzothienyl, thiazolyl, imidazolyl, oxazolyl, oxadiazolyl, thiadiazolyl,
benzotluazolyl, triazolyl, tetrazolyl, isoxazolyl, isothiazolyl, pyrrolyl, pyranyl,
tetrahydropyranyl, pyrazolyl, pyridyl, pyrimidinyl, quinolinyl, isoquinolinyl, purinyl,
carbazolyl, benzoxazolyl, benzimidazolyl, indolyl, isoindolyl, pyrazinyl. diazinyl,
pyrazine, triazinyltriaztne, tetrazinyl, and tetrazolyl. When substituted the substituted
group(s) is preferably one or more selected from alkyl, cycloalkyl, aryl, heteroaryl,
heteroalicyclic, hydroxy, alkoxy, aryloxy, heteroaryloxy, heteroalicycloxy,
thiohydroxy, thioaryloxy, thioheteroaryloxy, thioheteroalicycloxy, cyano, halogen,
nitro, carbonyl, O-carbamyl, N-carbamyl, C-amido, N-amido, C-carbox)', O-carboxy,
sulfinyl, sulfonyl, sulfonamido, trihalomethyl, ureido, amino, and -NRxRy, wherein Rx
andRy are as defined above.
As used herein, a "heteroalicyclic" group refers to a monocyclic or fused ring
group having in the ring(s) one or more atoms selected from the group consisting of
nitrogen, oxygen and sulfur. Rings are selected from those which provide stable
arrangements of bonds and are not intended to encomplish systems which would not
exist. The rings may also have one or more double bonds. However, the rings do not
have a completely conjugated pi-electron system. Examples, without limitation, of
heteroalicyclic groups are azetidinyl, piperidyl, piperazinyl, imidazolinyl,
thiazolidinyl, 3-pyrrolidin-l-yl, morpholinyl, thiomorpholinyl and tetrahydropyranyl.
When substituted the substituted group(s) is preferably one or more selected from
alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy, aryloxy,
heteroaryloxy, heteroalicycloxy, thiohydroxy, thioalkoxy, thioaryloxy,
thioheteroaryloxy, thioheteroalicycloxy, cyano, halogen, nitro, carbonyl, thiocarbonyl,
O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, C-thioamido,
N-amido, C-carboxy, O-carboxy, sulfinyl, sulfonyl, sulfonamido,
trihalomethanesulfonamido, trihalomemanesulfonyl, silyl, guanyl, guanidino, ureido,
phosphonyl, amino and -NRxRy, wherein Rx andRy are as defined above.
An "alkyl" group refers to a saturated aliphatic hydrocarbon including straight
chain and branched chain groups. Preferably, the alkyl group has 1 to 20 carbon
atoms (whenever a numerical range; e.g., "1-20", is stated herein, it means that the
group, in this case the alkyl group may contain 1 carbon atom, 2 carbon atoms, 3
carbon atoms, etc. up to and including 20 carbon atoms). More preferably, it is a
medium size alkyl having 1 to 10 carbon atoms. Most preferably, it is a lower allcyl
having 1 to 4 carbon atoms. The alkyl group may be substituted or unsubstituted.
When substituted, the substituent group(s) is preferably one or more individually
selected from trihaloalkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxy,
alkoxy, aryloxy, heteroaryloxy, heteroalicycloxy, thiohydroxy, thioalkoxy,
thioaryloxy, thioheteroaryloxy, thioheteroalicycloxy, cyano, halo, nitro, carbonyl,
thiocarbonyl, 0-carbamyl, N-carbamyl, 0-thiocarbamyl, N-thiocarbamyl, C-amido,
C-thioamido, N-amido, C-carboxy, 0-carboxy, sulfinyl, sulfonyl, sulfonamido,
trihalomethanesulfonamido, trihalomethanesulfonyl, and combined, a five- or sixmember
heteroalicyclic ring.
A "cycloalkyl" group refers to an all-carbon monocyclic or fused ring (i.e.,
rings which share and adjacent pair of carbon atoms) group wherein one or more
rings does not have a completely conjugated pi-electron system. Examples, without
limitation, of cycloalkyl groups are cyclopropane, cyclobutane, cyclopentane,
cyclopentene, cyclohexane, cyclohexadiene, cycloheptane, cycloheptatriene and
adamantane. A cycloalkyl group may be substituted or unsubstituted. When
substituted, the substituent group(s) is preferably one or more individually selected
from alkyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy, aryloxy, heteroaryloxy,
heteroalicycloxy, thiohydroxy, thioalkoxy, thioaryloxy, thioheteroaryloxy,
thioheteroalicycloxy, cyano, halo, nitro, carbonyl, thiocarbonyl., 0-carbamyl, Ncarbamyl,
0-thiocarbamyl, N-thiocarbamyl, C-amido, C-thioamido, N-amido,
C-carboxy, 0-carboxy, sulfinyl, sulfonyl, sulfonamido, trihalo- methanesulfonamido,
trihalomethanesulfonyl, silyl, guanyl, guanidino, ureido, phosphonyl, amino and
-NRxRy with Rx and Ry as defined above.
An "alkenyl" group refers to an alkyl group, as defined herein, consisting of at
least two carbon atoms and at least one carbon-carbon double bond.
An "alkynyl" group refers to an alkyl group, as defined herein, consisting of at
least two carbon atoms and at least one carbon-carbon triple bond.
A "hydroxy" group refers to an -OH group.
An "alkoxy" group refers to both an -O-allcyl and an -O-cycloalkyl group as
defined herein.
An "aryloxy" group refers to both an —0-aryl and an -O-heteroaryl group, as
defined herein.
A "heteroaryloxy" group refers to a heteroaryl-O- group with heteroaryl as
defined herein.
A "heteroalicycloxy" group refers to a heteroalicyclic-0- group with
heteroalicyclic as defined herein.
A "thiohydroxy" group refers to an -SH group.
A "thioalkoxy" group refers to both an S-alkyl and an -S-cycloalkyl group, as
defined herein.
A "thioaryloxy" group refers to both an -S-aryl and an — S-heteroaryl group, as
defined herein.
A "thioheteroaryloxy" group refers to a heteroaryl-S- group with heteroaryl as
defined herein.
A "thioheteroalicycloxy" group refers to a heteroalicyclic-S- group with
heteroalicyclic as defined herein.
A "carbonyl" group refers to a -C(=0)-R" group, where R" is selected from
the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl
46
(bonded through a ring carbon) and heteroalicyclic (bonded through a ring carbon), as
each is defined herein.
An "aldehyde" group refers to a carbonyl group where R" is hydrogen.
A "thiocarbonyl" group refers to a -C(=S)-R" group, with R" as defined
herein.
A "Keto" group refers to a -CC(-Q)C- group wherein the carbon on either or
both sides of the C=O maybe alkyl, c)'cloalkyl, aryl or a carbon of a heteroaryl or
heteroaliacyclic group.
A "trihalomethanecarbonyl" group refers to a ZsCCO)- group with said Z
being a halogen.
A "C-carboxy" group refers to a -C(=0)0-R" groups, with R" as defined
herein.
An "0-carboxy" group refers to a R"C(=::O)0-group, with R" as defined
herein.
A "carboxylic acid" group refers to a C-carboxy group in which R" is
hydrogen.
A "trihalomethyl" group refers to a -CZ3, group wherein Z is a halogen group
as defined herein.
A "trihalomethanesulfonyl" group refers to an Z3CS(=0)2- groups with Z as
defined above.
A "trihalomethanesulfonamido" group refers to a Z3CS(=0)2NRX- group with
•y
Z and R as defined herein.
A "sulfinyl" group refers to a -S(=0)-R" group, with R" as defined herein
and, in addition, as a bond only; i.e., -S(0)-.
A "sulfonyl" group refers to a -S(=0)2R" group with R" as defined herein
and, in addition as a bond only; i.e., -S(0)2-.
A "S-sulfonamido" group refers to a -S(=O)2NRXRY, with Rx and RY as
defined herein.
A "N-Sulfonamido" group refers to a R"S(=0)aNRx- group with Rx as
defined herein.
A "O-carbamyl" group refers to a -OC(=:O)NRxRy as defined herein.
A "N-carbamyl" group refers to a RxOC(=0)NRy group, with Rx and Ry as
defined herein.
A "O-thiocarbamyl" group refers to a -OC(=S)NRxRy group with Rx and Ry
as defined herein.
A "N-thiocarbamyl" group refers to a RxOC(=S)NRy- group with Rx and Ry as
defined herein.
An "amino" group refers to an -NH2 group.
A "C-amido" group refers to a -C(=0)NRxRy group with Rx and Ry as defined
herein.
A "C-thioamido" group refers to a -C(=S)NRxRy group, with Rx and Ry as
defined herein.
A "N-arnido" group refers to a RxC(=0)NRy- group, with Rx and Ry as
defined herein.
48
An "ureido" group refers to a -NRxC(=0)NRyRy2 group with Rx and Ry as
defined herein and Ry2 defined the same as Rx and Ry.
An "thioureido" group refers to a -NRxC(=S)NRyRy2 group with Rx and Ry as
defined herein and Ry2 defined the same as Rx and Ry.
A "guanidino" group refers to a -RxNC(=N)NRylly2 group, with Rx, Ry and
Ry2 as defined herein.
A "guanyl" group refers to a RxRyNC(=N)- group, with Rx and RY as defined
herein.
A "cyano" group refers to a-CN group.
A "silyl" group refers to a -Si(R")3, with R" as defined herein.
A "phosphonyl" group refers to a with Rx as defined herein.
A "hydrazino" group refers to a -NRxNRyRy2 group with Rx, Ry and Ry2 as
defined herein.
Any two adjacent R groups may combine to form an additional aryl,
cycloalkyl, heteroaryl or heterocyclic ring fused to the ring initially bearing those R
groups.
It is known in the art that nitogen atoms in heteroaryl systems can be
"participating in a heteroaryl ring double bond", and this refers to the form of double
bonds in the two tautomeric structures which comprise five-member ring heteroaryl
groups. This dictates whether nitrogens can be substituted as well understood by
chemists in the art. The disclosure and claims of the present invention are based on
the known general principles of chemical bonding. It is understood that the claims do
not encompass structures known to be unstable or not able to exist based on the
literature.
Physiologically acceptable salts of the prodrug compounds disclosed herein
are within the scope of this invention. The term "pharmaceutically acceptable salt" as
used herein and in the claims is intended to include nontoxic base addition salts. The
term "pharmaceutically acceptable salt" as used herein is also intended to include salts
of acidic groups, such as a carboxylate or phosphate or phosphate mono ester, with
such counterions as ammonium, alkali metal salts, particularly sodium or potassium,
alkaline earth metal salts, particularly calcium or magnesium, transition metal salts
such as zinc and salts with suitable organic bases such as lower alkylamines
(methylamine, ethylamine, cyclohexylamrne, and the like) or with substituted lower
alkylamines (e.g. hydroxyl-substituted alkylamines such as diethanolamine,
triethanolamine or mono tromethamine (also called TRIS or 2-amino-2~
(hydroxymethyl)propane-l,3-diol) tris(hydroxymethyl)-ammomethane), lysine,
arginine, histidine, N-methylglucamine, or with bases such as piperidine or
morpholine. It is understood that both pharmaceutically acceptable salts, when
isolated in solid or crystalline form., also include hydrates or water molecules
entrapped within the resulting Compound I substance. Stoichiometry possibilities are
well known to those in the art. Discussions of pharmaceutically acceptable salts and
lists of possible salts are contained in the following references:
Preparation of water-soluble compounds through salt formation. Stahl, P. Heinrich.
Cosmas Consult, Freiburg im Breisgau, Germany. Editor(s): Wermuth, Camille
Georges. Practice of Medicinal Chemistry (2nd Edition) (2003), 601-615.
Publisher: Elsevier, London, UK CODEN: 69EOEZ.
Handbook of pharmaceutical salts: properties, selection, and use by Stahl, P.
Heinrich, Wermuth, Camille G., International Union of Pure and Applied Chemistry.
Weinheim; New York: VHCA; Wiley-VCH, 2002.
hi another aspect of the invention, novel phosphate ester intermediate
Compounds II are disclosed.
hi the case of phosphate esters, the possibility of mono or bis exists and both
are covered by this invention.
In the method of the present invention, the term "antiviral effective amount"
means the total amount of each active component of the method that is sufficient to
show a meaningful patient benefit, i.e., healing of acute conditions characterized by
inhibition of the HIV infection. When applied to an individual active ingredient,
administered alone, the term refers to mat ingredient alone. When applied to a
combination, the term refers to combined amounts of the active ingredients that result
in the therapeutic effect, whether administered in combination, serially or
simultaneously. The terms "treat, treating, treatment" as used herein and in the claims
means preventing or ameliorating diseases associated with HIV infection.
The present invention is also directed to combinations of the compounds with
one or more agents useful in the treatment of AIDS. For example, the compounds of
this invention may be effectively administered, whether at periods of pre-exposure
and/or post-exposure, in combination with effective amounts of the AIDS antivirals,
immunomodulators, antiinfectives, or vaccines, such as those in the following table.
ANTJVIRALS
Drug Name Manufacturer Indication
097 Hoechst/Bayer HIV infection,
AIDS, ARC
(non-nucleoside
reverse transcriptase
(RT)
inhibitor)
Amprenavir
141 W94
GW141
Glaxo Wellcome HIV infection,
AIDS, ARC
(protease inhibitor)
Abacavir(1592U89)
GW 1592
Glaxo Wellcome HIV infection,
AIDS, ARC
(RT inhibitor)
Acemannan Carrington Labs
(Irving, TX)
ARC
Acyclovir Burroughs Wellcome HIV infection, AIDS,
ARC, in combination
with AZT
AD-439 Tanox Biosystems HIV infection, AIDS,
ARC
AD-519 Tanox Biosystems HIV infection, AIDS,
ARC
Adefovir dipivoxil
AL-721
Gilead Sciences
Ethigen
(Los Angeles, CA)
HIV infection
ARC, PGL
HIV positive, AIDS
Alpha Interferon Glaxo Wellcome Kaposi's sarcoma,
HIV in combination
Retrovir
Ansamycin
LM427
Adria Laboratories
(Dublin, OH)
Erbamont
(Stamford, CT)
ARC
Antibody which
Neutralizes pH
Labile alpha aberrant
Interferon
Advanced Biotherapy
Concepts
(Roclcville, MD)
AIDS, ARC
AR177 Aronex Pharm HIV infection, AIDS,
ARC
Beta-fluoro-ddA Nat'l Cancer Institute AIDS-associated
diseases
BMS-232623
(CGP-73547)
BMS-234475
(CGP-61755)
CI-1012
Cidofovir
Curdlan sulfate
Bristol-Myers Squibb/
Novartis
Bristol-Myers Squibb/
Novartis
Warner-Lambert
Gilead Science
AJIPharmaUSA
HIV infection,
AIDS, ARC
(protease inhibitor)
HIV infection,
AIDS, ARC
(protease inhibitor)
HIV-1 infection
CMV retinitis,
herpes, papillomavirus
HIV infection
Cytomegalovirus
Immune globin
Medlmmune CMV retinitis
Cytovene
Ganciclovir
Syntex Sight threatening
CMV
peripheral CMV
retinitis
Delaviridine
Dextran Sulfate
ddC
Dideoxycytidine
ddl
Dideoxyinosine
Pharmacia-Upj ohn
Ueno Fine Chem.
Ind. Ltd. (Osaka,
Japan)
Hoffman-La Roche
Bristol-Myers Squibb
HIV infection,
AIDS, ARC
(RT inhibitor)
AIDS, ARC, HIV
positive
asymptomatic
HIV infection, AIDS,
ARC
HIV infection, AIDS,
ARC; combination
with AZT/d4T
DMP-450 AVID
(Camden, NJ)
HIV infection,
AIDS, ARC
(protease inhibitor)
Efavirenz
(DMP 266)
(-)6-Chloro-4-(S)-
cyclopropylethynyl-
4(S)-trifluoromethyl-
1,4-dihydro-
2H-3,1 -b enzoxazin-
2-one, STOCRINE
53
DuPont Merck HIV infection,
AIDS, ARC
(non-nucleoside RT
inhibitor)
EL10 Elan Corp, PLC
(Gainesville, GA)
HIV infection
Famciclovir Smith Kline herpes zoster,
herpes simplex
FTC Emory University HIV infection,
AIDS, ARC
(reverse transcriptase
inhibitor)
GS840 Gilead HIV infection,
AIDS, ARC
(reverse transcriptase
inhibitor)
HBY097 Hoechst Marion
Roussel
HIV infection,
AIDS, ARC
(non-nucleoside
reverse transcriptase
inhibitor)
Hypericin VIMRx Pharm. HIV infection, AIDS,
ARC
Recombinant Human
Interferon Beta
Triton Biosciences
(Almeda, CA)
AIDS, Kaposi's
sarcoma, ARC
Interferon alfa-n3 Interferon Sciences ARC, AIDS
Indinavir Merck HIV infection, AIDS,
ARC, asymptomatic
HIV positive, also in
combination with
AZT/ddl/ddC
ISIS 2922 ISIS Pharmaceuticals CMV retinitis
KNI-272
Lamivudine, 3TC
Nat'l Cancer Institute
Glaxo Wellcome
HIV-assoc. diseases
HIV infection,
ADDS, ARC
(reverse
trans criptase
inhibitor); also
with AZT
Lobucavir
Nelfinavir
Nevirapine
Bristol-Myers Squibb
Agouron
Pharmaceuticals
Boeheringer
Ingleheim
CMV infection
HIV infection,
AIDS, ARC
(protease inhibitor)
HIV infection,
AIDS, ARC
(RT inhibitor)
Novapren Novaferon Labs, Inc.
(Akron, OH)
HIV inhibitor
Peptide T
Octapeptide
Sequence
Peninsula Labs
(Belmont, CA)
AIDS
Trisodium
Phosphonoformate
Astra Pharm.
Products, Inc.
CMV retinitis, HIV
infection, other CMV
infections
PNU-140690 Pharmacia Upjohn HIV infection,
AIDS, ARC
(protease inhibitor)
Probucol Vyrex HIV infection, AIDS
RBC-CD4 Sheffield Med.
Tech (Houston, TX)
HIV infection,
AIDS, ARC
Abacavir succinate
(or Ziagen®)

GSK
Bristol-Myers Squibb
Roche / Trimeris
Reyataz
(or atazanavir)
Fuzeon®
(or T-20)
Lexiva® GSK/Vertex
(or Fosamprenavir calcium)
HIV infection,
AIDS,
(reverse transcriptase
inhibitor)
HIV infection
AIDs, protease
inhibitor
HIV infection
AIDs, viral Fusion
inhibitor
HIV infection
AIDs, viral protease
inhibitor
IMAfUNOMODULATORS
Drug Name
AS-101
Bropirimine
Acemannan
Manufacturer
Wyeth-Ayerst
Pharmacia Upjohn
Carrington Labs, Inc.
(Irving, TX)
Indication
AIDS
Advanced AIDS
AIDS, ARC
CL246,738 American Cyanamid
Lederle Labs
AIDS, Kaposi's
sarcoma
FP-21399 Fuki IirjmunoPhann Blocks HIV fusion
with CD4+ cells
Gamma Interferon Genentech ARC, in combination
w/TNF (tumor
necrosis factor)
Granulocyte
Macrophage Colony
Stimulating Factor
Genetics Institute
Sandoz
AIDS
Granulocyte
Macrophage Colony
Stimulating Factor
Hoechst-Roussel
Immunex
AIDS
Granulocyte
Macrophage Colony
Stimulating Factor
Schering-Plough AIDS,
combination
w/AZT
HIV Core Particle
Immunostimulant
Rorer Seropositive HIV
IL-2
Interleukin-2
Cetus AIDS, in combination
w/AZT
IL-2
Interleukin-2
Hoffman-LaRoche
Immunex
AIDS, ARC, HIV, in
combination w/AZT
IL-2
Interleukin-2
(aldeslulcin)
Chiron AIDS, increase in
CD4 cell counts
Immune Globulin
Intravenous
(human)
Cutter Biological
(Berkeley, CA)
Pediatric AIDS, in
combination w/AZT
MREG-1 Imreg
(New Orleans, LA)
AIDS, Kaposi's
sarcoma, ARC, PGL
MREG-2 Imreg
(New Orleans, LA)
AIDS, Kaposi's
sarcoma, ARC, PGL
Imuthiol Diethyl
Dithio Carbamate
Merieux Institute AIDS, ARC
Alpha-2
Interferon
Schering Plough Kaposi's sarcoma
w/AZT, AIDS
Methionine-
Enkephalin
TNI Pharmaceutical
(Chicago, EL)
AIDS, ARC
MTP-PE
Muramyl-Tripeptide
Ciba-Geigy Corp. Kaposi's sarcoma
Granulocyte
Colony Stimulating
Factor
Amgen AIDS, in combination
w/AZT
Remime hiimune Response
Corp.
Inimunotherapeutic
rCD4
Recombinant
Soluble Human CD4
Genentech AIDS, ARC
rCD4-IgG
hybrids
AIDS, ARC
Recombinant Biogen
Soluble Human CD4
AIDS, ARC
rnterferon
Alfa2a
Hoffman-La Roche Kaposi's sarcoma
AIDS, ARC,
in combination w/AZT
SK&F106528
Soluble T4
Smith Kline HIV infection
Thymopentin Immunobiology
Research Institute
(Annandale, NJ)
HIV infection
Tumor Necrosis
Factor; TNF
Genentech ARC, in combination
w/gamma Interferon
ANTI-INFECTIVES
Drug Name
Clindamycin with
Primaquine
Fluconazole
Pastille
Nystatin Pastille
Ornidyl
Eflornithine
Manufacturer
Pharmacia Upjohn
Pfizer
Squibb Corp.
Merrell Dow
Pentamidiiie LyphoMed
Isethionate (IM & IV) (Rosemont, IL)
Trimethoprim
Indication
PCP
Cryptococcal
meningitis,
candidiasis
Prevention of
oral candidiasis
PCP
PCP treatment
Antibacterial
Trimethoprim/sulfa Antibacterial
Piritrexim Burroughs Wellcome PCP treatment
Pentaniidine
Isethionate for
Inhalation
Spiramycin
hitraconazole-
R51211
Fisons Corporation
Rhone-Poulenc
diarrhea
Janssen-Pharm.
PCP prophylaxis
Cryp'tosporidial
Histoplasmosis;
cryptococcal
meningitis
Trimetrexate Warner-Lambert PCP
Daunorubicin NeXstar, Sequus Kaposi's sarcoma
Recombinant Human Ortho Pharm. Corp.
Erythropoietin
Recombinant Human Serono
Growth Hormone
Megestrol Acetate Bristol-Myers Squibb
Testosterone Alza, Smith Kline
Severe anemia
assoc. with AZT
therapy
AIDS-related
wasting, cachexia
Treatment of
anorexia assoc.
W/AIDS
AIDS-related wasting
Total Enteral
Nutrition
Norwich Eaton
Pharmaceuticals
Diarrhea and
malabsorption
related to AIDS
Additionally, the compounds of the invention herein may be used in
combination with another class of agents for treating AIDS which are called HIV
entry inhibitors. Examples of such HIV entry inhibitors are discussed in DRUGS OF
THE FUTURE 1999,24(12), pp. 1355-1362; CELL, Vol. 9, pp. 243-246, Oct. 29,
1999; and DRUG DISCOVERY TODAY, Vol. 5, No. 5, May 2000, pp. 183-194 and
Inhibitors of the entry of HB into host cells. Meanwell, Nicholas A.; Kadow, John F.
Current Opinion in Drug Discovery & Development (2003), 6(4), 451-461.
Specifically the compounds can be utilized in combination Avith other attachment
inhibitors, fusion inhibitors, and chemokine receptor antagonists aimed at either the
CCR5 or CXCR4 coreceptor.
It will be understood that the scope of combinations of the compounds of this
invention with AIDS antivirals, immunomodulators, anti-infectives, HIV entry
inhibitors or vaccines is not limited to the list in the above Table but includes, in
principle, any combination with any pharmaceutical composition useful for the
treatment of AIDS.
Preferred combinations are simultaneous or alternating treatments with a
compound of the present invention and an inhibitor of HIV protease and/or a nonnucleoside
inhibitor of HIV reverse transcriptase. An optional fourth component in
the combination is a nucleoside inhibitor of HIV reverse transcriptase, such as AZT,
3TC, ddC or ddl. A preferred inhibitor of HIV protease is Reyataz® (active
ingredient Atazanavir). Typically a dose of 300 to 600mg is administered once a day.
This may be co-administered with a low dose of Ritonavir (50 to SOOmgs). Another
preferred inhibitor of HIV protease is Kaletra®. Another useful inhibitor of HIV
protease is indinavir, which is the sulfate salt of N-(2(R)-hydroxy-l-(S)-indanyl)-
2(R)-phenylmethyl-4-(S)-hydroxy-5-(l-(4-(3-pyridyl-methyl)-2(S)-NI-(tbutylcarboxamido)-
piperazinyl))-pentaneamide ethanolate, and is synthesized
according to U.S. 5,413,999. Indinavir is generally administered at a dosage of 800
mg three times a day. Other preferred protease inhibitors are nelfinavir and ritonavir.
Another preferred inhibitor of HIV protease is saquinavir which is administered in a
dosage of 600 or 1200 mg tid. Preferred non-nucleoside inhibitors of HIV reverse
transcriptase include efavirenz. The preparation of ddC, ddl and AZT are also
described in EPO 0,484,071. These combinations may have unexpected effects on
limiting the spread and degree of infection of HIV. Preferred combinations include
those with the following (1) indinavir with efavirenz, and, optionally, AZT and/or
3TC and/or ddl and/or ddC; (2) indinavir, and any of AZT and/or ddl and/or ddC
and/or 3TC, in particular, indinavir and AZT and 3TC; (3) stavudine and 3TC and/or
zidovudine; (4) zidovudine and lamivudine and 141W94 and 1592U89; (5)
zidovudine and lamivudine.
In such combinations the compound of the present invention and other active
agents may be administered separately or in conjunction, hi addition, the
administration of one element maybe prior to, concurrent to, or subsequent to the
administration of other agent(s).
ABBREVIATIONS
The following abbreviations, most of which are conventional abbreviations
well known to those skilled in the art, are used throughout the description of the
invention and the examples. Some of the abbreviations used are as follows:
h
r.t. =
mol =
mmol -
mg =
mL =
TFA =
DCE =
CH2C12
TPAP
THF
DEPBT
DMA
P-EDC
EDC
DMF
Hunig's Base =
MCPBA
azaindole =
4-azaindole =
5-azaindole =
6-azaindole =
7-azaindole =
4,6-diazaindole=
hour(s)
room temperature
mole(s)
millimole(s)
gram(s)
milligram(s)
milliliter(s)
Trifluoroacetic Acid
1,2-Dichloroethane
Dichloromethane
tetrapropylammonium perruthenate
Tetrahydofuran
3-(Diethoxyphosphoryloxy)-l,2,3-benzotriazin-4(3H)-
one
4-dimethylaminopyridine
Polymer supported l-(3-drniemylaminopropyl)-3-
ethylcarb odiimide
1 -(3-dimemylaminopropyl)-3 -ethylcarbodiimide
ATV-dimethylforrnamide
ATV-Diisopropylethylamine
meto-Chloroperbenzoic Acid
1 fl-Pyrrolo-pyridine
T-pyrrolo[3.,2-i]pyridine
lH-Pyrrolo[3,2-c]pyridine
lfl-pyrrolo[2,3-c]pyridine
lJ-Pytrolo[2,3-6]pyridine
5H-Pyrrolo [3,2-d]pyriniidine
5,6-diazaindole-
5,7-diazaindole=
PMB
DDQ
OTf
NMM
Pff-COPh
NaHMDS
EDAC
TMS "
DCM
DCE
MeOH
THF
EtOAc =
LDA
TMP-Li
DME
DIBALH
HOBT
CBZ
PCC
TRIS
l#-Pyrrolo[2,3-d]pyridazirie
7H-Pyrrolo[2,3-d]pyrimidine
4-Methoxyb enzyl
2, 3-Dichloro-5, 6-dicyano-l, 4-benzoquinone
Trifluoromethanesulfonoxy
4-Methylmorpholine
1 -Benzoylpiperazine
Sodium hexamethyldisilazide
l-(3-Dimetliylaminopropyl)-3-ethylcarbodiimide
Trimethylsilyl
Dichloromethane
Dichloroethane
Methanol
Tetrahydrofuran
Ethyl Acetate
Lithium diisopropylamide
2,2,6,6-tetramethylpiperidinyl lithium
Dimethoxyethane
Diisobutylaluminum hydride
1 -hydroxybenzotriazole
Benzyloxycarbonyl
Pyridinium chlorochromate
Tromethamine or 2-ammo-2-(hydroxymethyl)propane-
1,3-diol
CHEMISTRY
The present invention comprises compounds of Formula I, their
pharmaceutical formulations, and their use in patients suffering from or susceptible to
HIV infection.
Scheme A depicts an overview of the process for preparing the prodrugs I of
the invention from the parent molecules IV.
To elaborate on the method, as shown in Scheme A, the antiviral parent
compound of interest, IV, is converted into the phosphate intermediate II, byNalkylation
with chloride intermediate III, in the presence of a suitable base such as
sodium hydride, potassium hydride, sodium amide, sodium t-butoxide, sodium (bis
trimethylsilyl) amide, potassium (bis trimethyl silyl) amide, or combinations thereof
such as sodium hydride plus sodium bis (trimethylsilyl) amide. The preparation of
reagent HI and the methodology for use in preparing prodrugs by the alkylation
hydroxy groups has been described in Y. Ueda et.al. U.S. Patent 6,362,172B2 which
is incorporated by reference in its entirety. The alkylation conditions, protecting
groups, protecting group removal, and conditions for salt formation are in general
applicable to our application despite the fact that we are alkylating an azaindole in the
indole ring rather than a hydroxy group. In the current application, from 1.1 to 5.0
equivalents of base maybe utilized with between 2 and 4 equivalents being preferred.
From 1.1 up to 12 equivalents of reagent III may be used with 5 to 10 being preferred
depending on the substrate. The reagent may be added in one portion or
incrementally in several portions over time. A source of iodide ion is usually added
to the reaction to provide increased yields. Elemental iodine is currently preferred as
the source of iodide. 0.1 to 1.5 equivalents of iodine are usually added per
azaindole/indole NH being alkylated with 1.0 to 1.2 equivalents of iodine being
preferred since yields are highest. Alternate sources of iodide include, for example,
sodium iodide, lithium iodide, cesium iodide, copper iodide, or tetrabutyl ammonium
iodide. The function of iodine is presumably to generate the corresponding
iodomethyl reagent Ilia in situ from the chloro methyl reagent III. The iodo or bromo
reagents corresponding to III could likely be used directly in the reaction in place of
the chloride III. The alkylation reaction of step A is usually carried out in an inert
organic solvent such as tetrahydrofuran at a temperature from about 0°C to 50°C,
more preferably between 20° and 40°C. Other anhydrous organic solvents such as
methyl tetrahydrofuran, methyl t-butyl ether, dioxane, ethylene glycol dimethyl ether,
dimethyl acetamide, or N5N-dimethylfornianiide could also find utility. Ester
intermediate II is then subjected to a conventional deprotection step to remove the
protecting groups Pr. The reagents used in such step will depend on the protecting
group used, but will be well known to those skilled in the art. The most preferred
protecting group is the t-butyl group which can be removed with trifluoroacetic acid,
hydrochloric acid, or formic acid in an appropriate inert organic solvent. The inert
solvent can be dichloromethane, or possibly, for example, dichloroethane, toluene, or
trifluoromethyl benzene, hi methylene chloride, trifluoroacetic acid deprotection may
be effected using from 1 to 15 equivalents of acid (or the acid can be measured
differently as for example a 5% solution in solvent by volume) and temperatures of
between 0° and 40°. hi general, the greater excess of TFA employed, the lower the
temperature utilized. Exact conditions vary with substrate. Step 3 describes the
isolation of the free acid or salts which can be formed via many standard ways which
are well known in the art. Generally, following TFA deprotection, an aqueous
workup is employed in which the excess acid is neutralized with a base and the
organic impurities removed via extraction with an organic solvent such as ethyl
acetate or dichloromethane. For example excess aqueous NaOH may be used to
basify the reaction nixture. This is welt known to any chemist skilled in the art.
Reacidification of the aqueous phase to pH 2.5 with aqueous IN HC1 and then
extraction with an organic solvent will provide, after removal of solvent in vacuo., the
free acid. The free acid may be converted to inorganic salts by the addition of
appropriate bases in solvents such as water, methanol, ethanol, etc. For example,
addition of sodium carbonate to an aqueous solution of phosphate prodrug and
adjustment of the pH to approximately 7.6 provides a solution which upon removal of
water via lypohilization leaves the disodium salt of the prodrug. Potassium
carbonate could be used similarly. Aqueous solutions of sodium bicarbonate or
potassium bicarbonate could be used similarly. Mono potassium or mono sodium
salts could be generated via careful titration of phosphate acid solutions with
potassium or sodium 2-ethyl hexanoate. Amine salts can be generated by dissolving
the free acid in organic solvents such as ethyl acetate or acetom'trile or low molecular
weight alcohols or mixtures of these solvents optionally containing water. Some
amines potentially useful for salt formation include: lower alkylamines
(methylamine, ethylamine, cyclohexylamine, and the like) or substituted lower
alkylamines (e.g. hydroxyl-substituted alkylamines such as diethanolamine,
triethanolamine or tris(hydroxymethyl)-aminomethane), lysine, arginine, histidine, Nmethylglucamine,
or bases such as piperidine or morpholine. Slow addition of an
amine to a stirring solution at low temperature can provide either the mono of bis
amine salt depending on stoichiornetry. Amine salts can also be obtained by stirring
the solution and removing the solvent in vacuo rather than be crystallization or
precipitation. Recrystallization procedures will vary by compound and salt but are
available to one skilled in the art. Scheme B depicts a preferred sequence and set of
reagents and conditions for carrying out the general sequence shown in Scheme A.
An alternate and in many cases the preferred method for carrying out the sequence in
step C which includes the deprotection of the diester to provide the intermediate acid
insitu followed by salt formation in the reaction medium may be utilized. For
example, heating the diester II in a mixture of water and a water miscible cosolvent
such as for example acetone, methanol, ethanol, or isopropanol can produce the free
acid of I in the reaction medium (insitu). A preferred solvent is acetone and
isopropanol. Temperatures between ambient and the boiling points of the solvents
could be utilized. Typically 40° to 60° C is in the preferred range. Addition of a
base or more preferably an amine as described above to the reaction mixture
containing the free acid in the water and cosolvent can produce the salt directly. If
appropriate conditions are selected, the salt, may crystallize or precipitate directly
from the reaction medium and be isolated by filtration and drying. Specific examples
are contained in the experimental section.
The preferred method of preparation of intermediates Ha, lib, and lie and of
the acids lac, Ibc and Ic offers a number of significant advantages over the procedures
used initially for preparation of Ha, lib, and He during exploratory research efforts.
The initial discovery routes for the preparation of all three intermediates II used a
preparation of di-tertbutyl chloromethyl phosphate that required the use of relatively
expensive tetrabutylammonium di tert-butyl phosphate which was reacted with a 10
fold excess of expensive and potentially hazardous choro iodomethane. The excess
volatiles and iodomethane were removed in vacuo to provide the crude reagent which
was used without further purification. At least a 5 fold excess of this reagent was
used to react with compounds IV meaning that at least 5 equivalents of
tetrabutylammonium phosphate and 50 equivalents of choloriodomethane were used
as compared to quantities of either FVa, b or c. In addition, alleviation of compounds
IV with this reagent was achieved using Nail as base and iodine as an additive to
promote alkylation. These conditions produced a reaction mixture containing the
desired compound II as a major product and side products which were removed using
silica gel chromatography, a tedious, time consuming, and expensive operation
especially on reactions of increasing scale . Failure to remove side products, resulted
in products I from the next step, the removal of the protecting groups, that contained
impurities which were very difficult to remove in a satisfactory manner in either a
reasonable yield or time frame.
The improved preparation of di-tertbutyl chloromethyl phosphate utilizes less
expensive ditertbutyl potassium phosphate and only an approximate 2 fold excess of
this reagent as compared to the other reactant chloromethyl sulfonyl choride. The diterbutyl
chloromethyl phosphate prepared by this method is isolated in pure form via
convenient distillation.
For the conversion of IVa to Ha, only 1.2 equivalents of this reagent was used
to alkylate compounds IV. In addition, a less reactive and economical base,
potassium carbonate, was used in conjunction with DMSO to achieve an alkylation in
which the compounds II produced are sufficiently free of side products that they can
be used without chromatographic purification as inputs for the deprotection reaction.
The free acid lac or salts such as lab for example can be obtained in pure form from
Ha prepared in this manner without chromatography.
For the synthesis of compounds lib and lie which are slower to react than IVa,
2 to 2.5 equivalents of di-terbutyl chloromethyl phosphate were employed and
modified conditions (cesium carbonate as base with KI in the solvent, NMP) were
used to alkylate either IVb and IVc and realize high conversion to lib and He
respectively.
Again the new conditions provided compounds II in sufficient purity to allow
them to be used to produce compounds I without the need for chromatographic
purification. Thus the new conditions reduce the quantities and stoichiometry of
reagents needed to prepare the compound I of this invention and avoids the need for
chromatographic purification of intermediates II. The starting materials employed to
prepare the di-tertbutyl chloromethyl phosphate are more economical and less
hazardous and the final product is produced in higher purity. Finally, the conditions
developed for alkylating IVa, IVb, and IVc eliminate the need for the reactive,
flammable sodium hydride base that had been used in excess and employ either
potassium or cesium carbonate.
hi the alkylation step, a suitable base can be used such as MCOa (M is
lithium, sodium, potassium, rubidium or cesium). For converting IVa to Ha,
is preferred (1-5 molar equivalents, preferably 2 molar equivalents per mole of IVa).
For converting IVb to lib or IVc to He, cesium carbonate is preferred.
Also, a suitable solvent is needed such as dimethylsulfoxide, Ndimethylformamide,
acetone, acetonitrile, N-methylpyrrolidinone, formamide,
tetrahydrofuran, etc. (2-50 ml/gram of IV, with 5 ml/gram preferred);
dimethylsulfoxide is preferred in converting IVa to Ila; N-methylpyrrolidinone is
preferred in converting IVb to lib or IVc to He.
A suitable solvent iodine source includes, but is not limited to, MI (M is, for
example, lithium, sodium, potassium, iodine, tetrabutylammonium, etc.); with
potassium iodide preferred (0.1-5 molar equivalents/mole of Compound IV; 2
equivalents preferred).
The allcylating agent, di-tert-butyl chloromethyl phosphate, can be used in 1-
10 molar equivalents per mole of IV; but about 1.2 molar equivalents is preferred.
The reaction temperature can be 10-60 °C (30 °C preferred).
hi the deprotecting step, when the two tert-butyl groups are removed from Ila
to form lac, this is carried out in the presence of a suitable solvent such as
dichloromethane (preferred), dichloroethane, chloroform, carbontetrachloride,
toluene, benzene, etc. (2-50 ml/gram of IV, preferably 10 ml/gram)
For deprotecting lib and He to obtain Ibc and Ic, respectively, this is
accomplished in acetone/water at a temperature of about 40 °C.
Additionally, during deprotection of Ha, it is preferred to have an acid present
such as trifluoroacetic acid (preferred), hydrochloric, sulfuric, nitric, etc. (2-100
molar equivalents based on IVa, with 15 molar equivalents preferred).
CHEMISTRY
General:
Additional preparations of starting materials and precursors are contained in
Wang et. al. U.S. Patent 6,476,034 granted November 5, 2002 which is incorporated
by reference in its entirety.
All Liquid Chromatography (LC) data were recorded on a Shimadzu LC-
10AS liquid chromatograph using a SPD-10AV UV-Vis detector with Mass
Spectrometry (MS) data determined using a Micromass Platform for LC in
electrospray mode.
LC/MS METHOD (I.E., COMPOUND IDENTIFICATION)
Column A: YMC ODS-A S7 3.0x50 mm column
Column B: PHX-LUNA CIS 4.6x30 mm column
Column C: XTERRA ms CIS 4.6x30 mm column
Column D: YMC ODS-A CIS 4.6x30 mm column
Column E: YMC ODS-A CIS 4.6x33 mm column
Column F: YMC C18 S5 4.6x50 mm column
Column G: XTERRA CIS S7 3.0x50 mm column
Column H: YMC CIS S5 4.6x33 mm column
Column I: YMC ODS-A C18 S7 3.0x50 mm column
Column J: XTERRA C-l 8 S5 4.6x50mm column
Column K: YMC ODS-A CIS 4.6x33mm column
Column L: XterraMS CIS 5uM 4.6x30mm column
Column M: YMC ODS-A CIS S3 4.6x33mm column
STANDARD LC RUN CONDITIONS (USED UNLESS OTHERWISE NOTED):
Gradient: 100% Solvent A / 0% Solvent B to 0% Solvent A / 100%
Solvent B
Solvent A = 10% MeOH - 90% H2O - 0.1% TFA, Solvent B = 90% MeOH - 10%
H20 - 0.1% TFA; and Rtin min.
Gradient time: 2 minutes
Hold time 1 minute
Flow rate: 5 mL/min
Detector Wavelength: 220 run
Solvent A: 10% MeOH / 90% H2O 70.1% Trifluoroacetic Acid
Solvent B: 10% H20 / 90% MeOH / 0.1% Trifluoroacetic Acid
ALTERNATE LC RUN CONDITIONS B:
Gradient: 100% Solvent A / 0% Solvent B to 0% Solvent A /100%
Solvent B
Solvent A = 10% MeOH - 90% H20 - 0.1% TFA, Solvent B = 90% MeOH -10%
H20 - 0.1 % TFA; and Rt in min.
Gradient time: 4 minutes
Hold time 1 minute
Flow rate: 4 niL/min
Detector Wavelength: 220 nm
Solvent A: 10% MeOH / 90% H2O / 0.1 % Trifluoroacetic Acid
Solvent B: 10% H20 / 90% MeOH / 0.1 % Trifluoroacetic Acid
Compounds purified by preparative HPLC were diluted in MeOH (1.2 mL)
and purified using the following methods on a Shimadzu LC-10A automated
preparative HPLC system or on a Shimadzu LC-8A automated preparative HPLC
system with detector (SPD-IOAV UV-VIS) wavelength and solvent systems (A and
B) the same as above.
PREPARATIVE HPLC METHOD (I.E., COMPOUND PURIFICATION)
Purification Method: Initial gradient (40% B, 60% A) ramp to final gradient
(100% B, 0% A) over 20 minutes, hold for 3 minutes (100% B, 0% A)
Solvent A: 10% MeOH / 90% H20 / 0.1 % Trifluoroacetic Acid
Solvent B: 10% H2O / 90% MeOH / 0.1% Trifluoroacetic Acid
Column: YMC C18S520xlOO mm column
Detector Wavelength: 220 nm
For the experimental procedures below the following HPLC conditions or
modifications from the standard procedures were employed:
HPLC conditions for routine LC purity:
Detection at 254 nm; Gradient 0-100% B/A; A 10% CH3CN-90% H2O-0.1%
TFA, B 90% CH3CN-10% H2O-0.1% TFA; Gradient time 4 min; Column YMC
ODS-AQ or ORD-A 4.6x50mm 3 micron.
HPLC conditions for LC/MS analysis:
Column J: XTERRA C-18 S5 4.6x50mm column, Gradient: 100% Solvent A /
0% Solvent B to 0% Solvent A /100% Solvent B
Solvent A = 10% MeOH - 90% H2O - 0.1% TFA, Solvent B = 90% MeOH -10%
H2O - 0.1% TFA; and Rt in min; Gradient time: 3 minutes; Flow rate: 4
mL/min; Detector Wavelength: 220 nm
Starting materials, can be purchased from commercial sources or prepared
using literature procedures.
PREPARATION OF PARENT COMPOUNDS IV:
The preparation of parent Compounds IV has been described previously in the
following, all of which are herein incorporated by reference in their entirety as
follows:
U.S. Patent 6,469,006 granted October 22, 2002 to W. S. Blair et al;
U.S. Patent 6,476,034 granted November 5, 2002 to Wang et al;
U.S. Patent 6,573,262 granted June 3, 2003 to Meanwell et al;
U.S. Serial Number 10/630,278 filed July 30, 2003 to J. Kadow et al; which is a
continuation-in-part of U.S. Serial Number 10/214,982 filed August 7, 2002, which is
a continuation-in-part of U.S. Serial Number 10/038,306 filed January 2,2002, which
corresponds to PCT WO 02/062423, filed January 2,2002, published August 15,
2002;
U.S. Serial Number 10/871,931 filed June 18,2004 to Yeung et al;
U.S. Serial Number 10/762,108 filed January 21,2004 to Wang et al, corresponding
to PCT WO 2004/043337 published May 27,2004.
Select detailed procedures are provided below:
TYPICAL PROCEDURE FOR THE PREPARATION OF INTERMEDIATES FOR
THE PREPARATION OF PARENT COMPOUNDS IV
1) Preparation ofAzaindole 1
Preparation of azaindole, Method A: Preparation of 7-Chloro-6-
azaindole le: 2-Chloro-3-nitropyridine 22e (5.0 g) was dissolved in dry THF (200
ml). After the solution was cooled down to -78°C, an excess of vinyl magnesium
bromide (1.0 M in THF, 100 ml) was added. Then, the reaction was left at -20°C for
eight hours before being quenched with 20% NH4C1 (150 ml). The aqueous phase
was extracted with EtOAc (3 x 150 ml). The combined organic layer was dried over
MgSO4. After filtration and concentration, the crude product was purified by silica
gel column chromatography to afford 1.5 g of 7-chloro-6-azaindole le in 31% yield.
Compounds San, IVa and Sap are described below.
Compound lam, 4-bromo-7-chloro-6-azaindole (yellow solid) was prepared
by the same method used for azaindole le but the starting material employed was 5-
bromo-2-chloro-3-nitropyridine. (available from Aldrich, Co.). MS m/z: (M+H)+
calcd for C7H5BrClN2: 230.93; found 231.15. HPLC retention time: 1.62 minutes
(column B).
Compound Ian (4-rnethoxy-7-chloro-6-azaindole) and compound lao (4,7-
dimethoxy-6-azaindole): A mixture of 4-bromo-7-chloro-6-azaindole (1 g), Cul (0.65
g) and NaOMe (4 ml, 25%) in MeOH (16 ml) was heated at 110 - 120°C for 16
hours in a sealed tube. After cooling to ambient temperature, the reaction mixture
was neutralized with IN HCI to achieve pH 7. The aqueous solution was extracted
with EtOAc (3 x 30ml). Then the combined organic layer was dried over MgSO4 and
concentrated in vacuo to afford a residue, which was purified by silica gel (50 g)
chromatography using 1:7 EtOAc : hexane as the eluent. (Column dimension: 20mm
x 30 cm) to give 0.3 g of 4-methoxy-7-chloro-6-azaindole (white solid) and 0-1 g of
4,7-dimethoxy-6-azaindole (white solid).
Compound Ian (4-methoxy-7-chloro-6-azaindole). MS m/z: (M+H)+ calcd
for C8H8C1N20: 183.03; found 183.09. HPLC retention time: 1.02 minutes (column
B).
Compound lao (4,7-dimethoxy-6-azaindole). !H NMR (500 MHz, CDC13) 6
7.28 (m, 2H), 6.63 (m, 1H), 4.14 (s, 3H), 3.95 (s, 3H). MS m/z: (M+H)+ calcd for
C9HiiN202: 179.08; found 179.05. HPLC retention time: 1.36 minutes (column B).
Acylation ofazaindole, method B: Preparation of Methyl (5-azaindol-3-yl)-
oxoacetate 2b: 5-Azaindole (Ib) (0.5 g, 4.2 mmol) was added to a suspension of
A1C13 (2.8 g, 21.0 mmol) in CH2C12 (100 ml). Stirring was continued at room
temperature for 1 hour before methyl chlorooxoacetate (2.5 g, 21.0 mmol) was added
dropwise. The reaction was stirred for 8 hours. After 20ml of MeOH was added
cautiously to quench the reaction, solvents were removed under vacuum. The solid
residue was purified by silica gel column chromatography (EtOAc/MeOH = 10 : 1) to
afford 0.6 g (70%) of the acylated product 2b.
Characterization of compounds 2:
Compound 2b (Methyl (5-azaindol-3-yl)-oxoacetate): !H NMR (500 MHz,
CD3OD) 8 9.61 (s, 1H), 9.02 (s, 1H), 8.59 (d, 1H, J- 6.63 Hz), 8.15 (d, 1H, J- 6.60
Hz), 4.00 (s, 3H); 13C NMR (125 MHz, CD3OD) 8 178.9,163.0, 145.6,144.2,138.3,
135.0, 124.7, 116.3, 112.1, 53.8. MS m/z: (M+H)+ calcd for CioH9N2O3: 205.06;
found 205.04. HPLC retention tune: 0.32 minutes (column A).
Compound 2ao (Ethyl (4,7-dimethoxy-6-azaindol-3-yl)-oxoacetate) was
prepared by the same method as used for compound 2b but the starting material
employed was 4,7-dimethoxy-6-azaindole. The compound was purified by silica gel
chromatography using 2 : 3 EtOAc : Hexane as the eluent to give a yellow oil: !H
NMR (500 MHz, CDC13) 5 9.50 (s, 1H), 8.21 (s, 1H), 7.47 (s, 1H), 4.39 (q, 2H, d-
7.05 Hz), 4.13 (s, 3H), 3.93 (s, 3H), 1.40 (t, 3H, d-1.1 Hz). MS m/z: (M+H)+ calcd
for Ci3Hi5N2O5: 279.10; found 279.16. HPLC retention time: 1.28 minutes (column
B).
Preparation of Potassium (7-azaindol-3-yl)-oxoacetate 3a: Compound 2a (43
g, 0.21 mol) and K2C03 (56.9g, 0.41 mol) were dissolved in MeOH (200 ml) and
H20 (200 ml). After 8 hours, product 3a precipitated out from the solution.
Filtration afforded 43 g of compound 3 a as a white solid in 90.4% yield.
Characterization of compounds 3:
Compound 3a, Potassium (7-azaindol-3-yl)-oxoacetate: H NMR (300 MHz,
DMSO-d6) 8 8.42 (d, 1H, J- 7.86 Hz), 8.26 (d, 1H, J- 4.71 Hz), 8.14 (s, 1H), 7.18
(dd, 1H, J= 7.86, 4.71Hz); 13C NMR (75 MHz, DMSO-d6) 8 169.4, 148.9,143.6,
135.1, 129.3, 118.2, 117.5, 112.9. MS m/z: (M+H)+of fee corresponding acid of
compound 3a (3a-K+H) calcd for CgHyNOs: 191.05; found 190.97. HPLC retention
time: 0.48 minutes (column A).
Compound Sao (Potassium (4,7-dimethoxy-6-azaindol-3-yl)-oxoacetate) was
prepared (as a yellow solid), by the same method used to prepare compound 3 a
except Ethyl (4,7-dmiethoxy-6-azaindol-3-yl)-oxoacetate was employed as the
starting material. MS 777/2: (M+H)+ of the corresponding acid of compound 3ao (MK+
H)+ calcd for CiiHiiN2O5: 251.07; found 251.09. HPLC retention time: 0.69
minutes (column B).
Example Procedure Prep of 5a
Preparation of(R)-N-(benzoyl)-3-methyl~N'-[(7-azaindol~3-yl)-oxoacetyl]-
piperazine 5a: Potassium 7-azaindole 3-glyoxylate 3a (25.4 g, 0.111 mol), (R)-
methyl-N-benzoylpiperazine 4a (22.7 g, 0.111 mol), 3-(diethoxyphosphoryloxy)-
l,2,3-benzotriazin-4(3#)-one (DEPBT) (33.3 g, 0.111 mol) and Hunig's Base (28.6
g, 0.222 mol) were combined in 500 ml of DMF. The mixture was stirred at room
temperature' for 8 hours.
DMF was removed via evaporation at reduced pressure and the residue was
partitioned between ethyl acetate (2000 ml) and 5% Na2COa aqueous solution (2 x
400 ml). The aqueous layer was extracted with ethyl acetate (3 x 300 ml). The
organic phase combined and dried over anhydrous MgSC4. Concentration in vacua
provided a crude product, which was purified by silica gel column chromatography
with EtOAc/MeOH (50:1) to give 33 g of product 5a in 81% yield.
Characterization of compounds 5 with the following sub-structure:
Compound 5a, n = 2, R7.13 = H, R14 = (#)-Me, (R)-N-(benzoyl)-3-methyl-N'-
[(7-azaindol-3-yl)-oxoacetyl]-pipemzine: lll NMR (300 MHz, CD3OD) 8 8.57 (d,
IH, J = 5.97 Hz), 8.38 (d, IH, J = 4.20 Hz)3 8.27 (m, IH), 7.47 (s, 5H), 7.35 (t, IH, J
= 5.13 Hz), 4.75-2.87 (m, IE), 1.31 (b, 3H); 13C NMR (75 MHz, CD3OD) 5 185.6,
172.0,166.3, 148.9, 144.6, 137.0, 134.8, 130.2, 129.9, 128.4, 126.6, 118.6, 118.0,
112.2, 61.3, 50.3, 45.1, 35.5, 14.9, 13.7. MS m/z: (M+H)+ calcd for C2iH2iN403:
377.16; found 377.18. HPLC retention time: 1.21 minutes (column A). Anal. Calcd
for C2iH20N403: C, 67.01; H, 5.36; N, 14.88. Found: C, 66.01; H, 5.35; N, 14.61.
Compound IVa, N-(benzoyl)-N'-[(4,7-dimethoxy-6-azaindol-3-yl)-
oxoacetyljpiperazine, was prepared by the same method used to prepare compound
5a but the starting material was Potassium (4,7-dimethoxy-6-azaindol-3-yl)-
oxoacetate. The compound was purified by silica gel chrornatography using EtOAc
as the eluting solvent to give a white solid. 1E NMR (500 MHz, DMSO-d6) 6 13.0 (s,
IH), 8.15 (s, IH), 7.40 (m, 6H), 4.00 (s, 3H), 3.83 (s, 3H), 3.63-3.34 (m, 8H); 13C
NMR (125 MHz, DMSO-d6) 5 185.5, 169.3,166.5,146.2, 145.7,136.6,135.3, 129.6,
128.4, 126.9,122.2,122.1,119.2, 114.4, 56.8, 52.9,45.5, 39.9. MS m/z: (M+H)+
calcd for C22H23N405: 423.17; found 423.19. HPLC retention time: 1.33 minutes
(column B). Anal. Calcd. For C22H2iN4O5: C, 62.7; H, 5.02; N, 13.29. Found: C,
61.92; H, 5.41; 13.01. Melting Point: 229.5-232°C.
PROCEDURES FOR PREPARATION OF PARENT COMPOUND TVC
Preparation of3-methyl-l,2,4-triazole (2-81)
Procedure: A solid mixture of formic hydrazide (68 g, 1.13 mol) and thioacetamide
(85 g, 1.13 mol) in a SOOmL-round bottom flask was heated with stirring at 150°C
(oil batli temp.) for 1.5 hrs with a gentle stream of nitrogen, removing HaS and water
(about 18 mL of liquid collected) formed during the reaction. The reaction mixture
was distilled under reduced pressure, collecting 60.3 g (0.726 mol, Y. 63.3%) of the
title compound at 102°C / 0.35-1 mmHg as a white solid after removing a liquid
forerun.: JH NMR (CDC13) Sppm 2.51 (3H, s, 3-Me), 8.03 (lH,.s, 5-H), 9.5 (1H, br,
NH); TLC Rf (10% MeOH/CH2Cl2) = 0.3 (phosphomolybdate-charring, white spot).
Reference: Vanek, T.; Velkova, V.; Gut, Jiri Coll. Czech. Chem. Comm. 1985, 49,
2492.
Procedure: A 500 mL round bottom flask was loaded with 4-methoxy-7-chloro-6-
azaindole 2e (9.1 g, 50 mmol; dried in vacud), potassium carbonate (13.8 g, 100
mmol, 2 eq.), copper powder (6.35 g, 100 mmol, 2 eq.), and 3-methyl-l,2,4-triazole
(83 g, 1.0 mol, 20 eq.). The solid mixture was heated to melt at 170-175°C (external
oil bath temperature) under a gentle stream of anhydrous nitrogen for 12 h, by which
time HPLC analysis indicated that the amount of the peak for the starting material
had become 5-30% and the desired product peak becomes about 45% with isomeric
by-product peak becomes 15%. As the reaction mixture cooled, MeOH (150 mL)
was added slowly to the warm, stirred mixture. Upon cooling, the insoluble material
(copper powder) was filtered through a Celite pad, and rinsed with methanol. The
filtrate was concentrated in vacua to a thick paste which was diluted with water (1 L)
and extracted with EtOAc (3xl50mL). The EtOAc extracts were dried (MgSO),
filtered and concentrated to obtain about 8 g of crude residue which was crystallized
by dissolving in hot CHsCN (50 mL), followed by diluting with water (100 mL) and
cooling at 0°C to collect 1.45 g (12.7%) of the title compound as white solid. The
filtrate was purified by C-18 reverse phase silica gel (YMC ODS-A 75 jmi) eluted
with 15-30% CHsCN/PIzO. Appropriate fractions were combined and the aqueous
solution after removing CHsCN by rotary evaporator was lyophilized to give
additional 1.15 g of the title compound 3-81. The crude aqueous layer was further
extracted with EtOAc several times. The ethyl acetate extracts were dried (MgSO4),
filtered, concentrated, and crystallized from MeOH to give additional 200 mg of the
title compound 3-81. The total yield: 2.8 g (12.2 mmol, Y. 24.5%); MS m/z 230
(MH), HRMS (ESI) m/z calcd for CnHi2N5O (M+H), 230.1042, found 230.1038 (A -
1.7 ppm); 1E NMR (CDC13) Sppm 2.54 (3H, s, CH3), 4.05 (3H, s, OCH3), 6.73 (1H,
s, H-3), 7.40 (1H, s, H-2), 7.56 (1H, s, H-5), 9.15 (1H, s, triazole-H-5); 13C NMR
(CDC13,125.7 MHz) 8 ppm 14.2 (triazole-Me), 56.3 (OMe), 100.5 (C-3), 116.9 (C-
5), 123.5,127.2, 127.5 (C-2), 129.5 (C-7), 141.2 (C-5'), 149.5 (C-4), 161.8 (C-3');
Anal. Calcd for CnHnN50: C 57.63, H 4.83, N 30.55, found C 57.37, II 4.64, N
30.68.
The structure was confirmed by a single X-ray crystallographic analysis using crystals
obtained from C-18 column fractions. A portion of C-18 column fractions containing
a mixture of the desired 3-methyl-l,2,4-triazolyl analog 3-81 and isomeric 5-methyl-
1,2,4-triazolyl analog 4-81 was further purified by C-18 reverse phase column eluting
with 8-10% CHsCN/HsO. Appropriate fractions were extracted with CHbCk, and
slow evaporation of the solvent gave crystalline material of the isomeric 7-(5-methyl82
l,2,4-triazolyl)-4-methoxy-6-azaindole (4-81): MS m/z 230 (MH), 'HNMR (CDC13)
5ppm 3.05 (3H, s, CH3), 4.07 (3H, s, OCH3), 6.74 (1H, q, J=2.4, H-2), 7.37 (1H, t,
J=2.4, H-3), 7.65 (1H, s, H-5), 8.07 (1H, s, triazole-H-3). The structure was
confirmed by a single X-ray crystallographic analysis.
Procedure: A1C13 (40 g, 0.3 mol, 15 eq.) was dissolved in a solution of CHaCla (100
mL) and nitromethane (20 mL) under dry nitrogen. To this solution was added
compound 3-81 (4.58 g, 0.02 mol) under stirring and under No, followed by methyl
chlorooxoacetate (9.8 g, 0.08 mol, 4 eq.). The mixture was stirred under N2 at room
temperature for 1.5 h. The mixture was added drop-wise to a cold and stirred
solution of 20% aqueous ammonium acetate solution (750 mL). The mixture was
stirred for 20 min and the resultant precipitate was filtered, washed thoroughly with
water and dried in vacuo to obtain 4.7 g (0.015 mol, Y. 75%) of the title compound 5-
81 as white solid: MS m/z 316 (MH); HRMS (ESI) m/z calcd for C14Hi4NsO4
(M+H), 316.1046; found 316.1041 (A -1.6 ppm); [H NMR (CDC13, 500 MHz) 8ppm
2.58 (3H, s, CH3), 3.96 (3H, s, OCH3), 4.05 (3H, s, OCH3), 7.76 (1H, s, H-5), 8.34
(1H, d, J=3Hz, H-2), 9.15 (1H, s, triazole-H-5), 11.0 (1H, brs, NH). More title
compound 5-81 and hydrolyzed acid 6-81 can be obtained from the filtrate by acidbase
extraction with EtOAc.
Procedure: To a suspension of me methyl ester 5-81 (2.2 g, 7.0 mmol) in MeOH (50
mL) was added 0.25M NaOH solution in water (56 mL, 14 mmol, 2 eq.) at room
temperature and the mixture stirred for 15 min by which time HPLC indicated the
hydrolysis was complete. The mixture was concentrated in vacua quickly to remove
MeOH, and to the residual solution was added water (100 mL) and IN HC1 (14 mL)
with stirring to neutralize the mixture. The resultant fine precipitate was filtered,
washed with water and dried in vacua to obtain 1.98 g ( 6.58 mmol, Y. 94%) of the
title compound 6-81 as off-white solid: MS m/z 302 (MH); JH NMR (DMSO-cfe, 500
MHz) 6 ppm 2.50 (3H, s, overlapped with DMSO peaks), 3.98 (3H, s, CH3O), 7.87
(1H, s, H-5), 8.29 (1H, d, J=3.5Hz, H-2), 9.25 (1H, s, triazole-H-5), 12.37 (1H, s,
NH).
Alternative procedure: To a suspension of the methyl ester 5-81 (10.7 g, 34 mmol) in
MeOH (150 mL) was added 0.25M NaOH solution in water (272 mL, 68 mmol, 2
eq.) at room temperature and the mixture stirred for 20 min by which time HPLC
indicated the hydrolysis was complete. The mixture was concentrated in vacua
quickly to remove MeOH, and the residual solution was extracted with EtOAc to
remove any neutral impurities. To the aqueous phase was added IN HC1 (68 mL, 68
mmol) to neutralize the product. The resultant mixture was frozen and lyophilized to
obtain 14.1 g (33.7 mmol, Y. 99.2%) of the title compound 6-81, containing 2 mole
equivalents of NaCl as off-white solid. This material was used in the subsequent
reaction without further purification. The disodium salt of the title compound 6-81
was obtained by C-l 8 reverse phase column chromatography after sodium
bicarbonate treatment: HPLC >97% (AP, uv at 254nm); HRMS (Na salt, ESI") m/z
calcd for C13H10N5O4 (M-H), 300.0733; found 300.0724 (A -3 ppm); LHNMR (Na
salt, DMSO-Jg, 500 MHz) 8 ppm 2.37 (3H, s, Me), 3.83 (3H, s, CH3O), 7.56 (IH, s,
H-5), 8.03 (IH, s, H-2), 9.32 (IH, s, triazole-H-5); 13C NMR (Na salt, DMSO-d6,
125.7 MHz) 6 ppm 13.8 (triazole-Me), 57.2 (OMe), 114.8 (C-3), 120.0 (C-5), 125.1,
143.5 (C-5'), 149.8 (C-4), 160.0 (C-3'), 171.7, 191.3.
Preparation of Compound We
Procedure: To a solution of the acid 6-81 (3.01 g, 10 mmol) and benzoylpiperazine
hydrochloride (3.39 g, 15 mmol) in DMF (50 mL) was added triethylamine (10.1 g,
100 mmol, 10 eq.), followed by l-[3-(dimethylaniiiio)propyl]-3-ethylcarbodiimide
hydrochloride (EDC; 5.75 g, 30 mmol) under N2 and the mixture stirred at room
temperature for 22 h after sonication and at 40°C for 2 h. The mixture was
concentrated in vacua to remove DMF and TEA, and to the residual solution was
added water (200 mL) under stirring and sonication. The precipitates formed were
collected, washed with water and dried in vacua to obtain 2.8 g (5.9 mmol, Y. 59%)
of the title compound IVc as off-white solid. The filtrate was extracted with CH2C12
(x2). The CH2C12 extracts were dried (Na2S04), filtered and concentrated to gum
which was triturated with Et20 to obtain a solid. This solid was suspended and
triturated with MeOH to obtain 400 mg of the title compound IVc as off-white solid.
Total yield: 3.2 g (6.8 mmol, Y. 68%): MS m/z 474 (MH); HUMS (ESI) m/z calcd
for C24H24N704 (M+H) 474.1890, found 474.1884 (A -1.2 ppm); 1E NMR (DMSOd6)
8 ppm 2.50 (3H, s, overlapped with DMSO peaks), 3.43 (4H, br, CH2N), 3.68
(4H, br, CH2N), 3.99 (3H, s, CH3O), 7.46 (5H, br. s, Ar-Iis), 7.88 (IH, s, indole-H-5),
8.25 (IH, s, indole-H-2), 9.25 (IH, s, triazole-H-5), 12.40 (IH, s, NH); 13C-NMR
(DMSO-J6) 8 ppm 13.78, 40.58, 45.11, 56.78, 114.11, 120.95, 122.71,123.60,
126.98, 128.34, 129.6, 135.43, 138.52, 142.10, 149.15, 161.29, 166.17, 169.22,
185.42; UV (MeOH) tanax 233.6 nm (e 3.43xl04), 314.9 nm (e 1.73xl04); Anal:
Calc for C24H24N704.1/5H20; C 60.42, H 4.94, N 20.55, Found; C 60.42, H 5.03, N
20.65; KF (H2O) 0.75%.
This reaction can also be performed by use of HATU and DMAP to provide more
consistent yield of the title compound: To a suspension of the acid 6-81 (15.6 mmol)
and HATU [O-(7-azabenzotriazol-l-yl)-N,N,N',N'-tetramethyluronium
hexafluorophos phonate] (8.90 g, 23.4 mmol; 1.5 eq.) in DMF (60 mL) and CH2C12
(60 mL) was added a mixture of DMAP (5.72 g, 46.8 mmol, 3 eq.) and
benzoylpiperazine hydrochloride (5.30 g, 23.4 mmol; 1.5 eq.) in DMF (60 mL) at
room temperature and the mixture was stirred under nitrogen atmosphere for 4 hrs.
The mixture was concentrated in vacua to remove CHaCk and most of DMF, and to
the residual solution was added water under stirring and sonication. The precipitates
formed were collected, washed with water and dried in vacuo to obtain 5.38 g (1 1 .4
mmol, Y. 72.8%) of the title compound IVc as off-white solid: HPLC >95% (AP, uv
at 254nm).
Synthetic Experimental Procedures for best preparation of'CompoundWb
5-Amino 2 methoxypyridine (50g, 0.4mol) was added to a stirring mixture of
absolute ethanol (280 ml) and HBF4 (48% in water, 172 ml) and cooled to 0°C.
Sodium nitrite (129g) was dissolved in water (52 ml) and added portion-wise over
Ih). The stirring was continued at 0°C for 2hr, The reaction mixture was diluted
with ether (1L). The solid product was collected by filtration and washed with 500
ml of 50:50 EtOH/ether and subsequently several times with ether until the product
was slightly pinkish in color. The pale pink solid 90g (~100% yield) was kept in a
dessicator over P2Os.
The same procedure was followed to perform the reaction on larger scale:
(1) (200g, 1.6mol); HBF4 (688 ml); NaNO2 (116 g); EtOH (1.12 L); H2O (208 ml)
The reaction was run 4 times (total 800 grams (1-80)). The product was dried over
P205 for 48 hr. (only 24hr for first batch).
A total of 1,293 g of (2-80) was obtained, (91% yield).
Ref: J. Heterocyclic Chem., 10, 779, 1973 (for above reactions, including analytical
data)
The decomposition of the diazonium salt was run in 3 batches of:
206g, 219g and 231g using 1.3L, 1.4L and 1.6L of anhydrous toluene respectively.
The toluene was preheated under nitrogen to 100°C (internal temperature) in a 2L 3-
neck round bottom flask provided with a mechanical stirrer. The solid was added
solid portion-wise via a scoop through a powder funnel which was attached to an
adapter with slight outward positive nitrogen flow. During addition, the temperature
was maintained between 99-102°C (set at 100°C) and stirred vigorously. Total
addition time was 60 min. for the smaller two batches and 70 min. for the last one.
After the addition was finished, each stirring reaction was heated at 110°C for Ihr.
The heating mantle was removed and stirring was stopped. The reactions were
allowed to stand for 2hr (ambient temp achieved). Safety Note: The reaction contains
BF3 so working with the reaction hot exposes vapors which caused skin irritation
with some people. No incidents were noted at ambient temperature (6 different
people). The hot toluene from the reaction was poured into a 4L Erlenmeyer (a dark
brown oil and residue remained in the flask). The residue was washed with 50 ml of
toluene and poured into the original toluene extracts.
Add 1.5L of IN NaOH to toluene layer, extract and wash with ~100 ml of sat aq.
NaCl.
Combine NaCl with NaOH layer, re-extract with 150 ml of toluene, wash with 50ml
ofsatNaCl.
Combine toluene layers.
Add 1L of IN NaOH to residue in reaction flask and swirl to dissolve as much
residue as possible then add 500ml Et20 and pour into Erlenmeyer.
Add ~500ml more of 1 N NaOH to reaction flask and swirl ~500ml of Et2O.
Combine dark Et20 and NaOH washings in erlenmyer flask.
Et2O/NaOH mixture was poured through powder funnel containing plug of glass
wool to collect dark viscous solid. (Add ~500ml more ether to wash) into 6L sep
funnel.
Extract. Wash ether layer with ~200ml of H20 and then 100ml of sat NaCl.
Combine all washings with original NaOH aq. Layer and re-extract with 500ml of
ether. Wash with 100ml H20 and 100ml of NaCl.
Combine ether extracts. Toluene and ether extracts were checked by LC/MS clean
product.
The ether was concentrated on a rotovap and the residue was combined with the
toluene extracts to make a homogeneous solution which is taken to next step as is.
The other two runs were combined and worked up in the same way.
All aqueous layers were checked by LC/MS = no product.
Ref: J. Heterocyclic Chem., 10, 779, 1973 (for above reactions, including analytical
data)
A total of 4.6L of toluene solution containing 3-80 was placed in several sealed tubes
and treated Avith 900ml of 35% HC1 at 145°C for 2hr. LC/MS showed no starting
material, only 4. The toluene solution was decanted and discarded. The aqueous
phase was washed with EtOAc and concentrated down to remove volatiles to afford a
brown solid containing the desired fluoro-hydroxypyridine 4-80.
A total of 244g of this solid was collected and taken to next step as is (it was not
completely dry).
Note: We have subsequently run this by decanting the toluene layer first prior to
heating to reduce volumes. Same reaction was carried out using HBr (48% in H20)
at 100°C for 6h with similar result to the literature procedure 49% yield.
Ref: J. Heterocyclic Chem., 10, 779, 1973 (for above reactions, including analytical
data)
The solid from above containing (4-80) was divided in 4 batches and treated
with H2SC>4 and fuming HNOs as shown below. The amounts used were:
batch 1
25g
20.8ml
5.6mH-
56ml
batch 2
54g
45ml
12ml+
120ml
batch 3
75g
62.4ml
16.8ml+
168ml
batch 4
90g
75ml
20ml+
200ml
Compound 4-80 was dissolved in sulfuric acid (the larger amounts indicated above)
at rt and then heated to 65°C. A preformed solution of fuming nitric acid and sulfuric
acid (the smaller amount indicated above) was added dropwise. The temperature was
kept between 65°C and 80°C (rxn is exothermic and although the bath is at 65°C,
temperature goes higher, usually 75, sometimes 80°C). After the addition was
complete, the reaction mixture was heated at 65°C for an additional hr. The reaction
mixture was then cooled to rt and poured in a flask containing ice) (20g of ice/gr
compound, evolution of gas occurred). A solid precipitated out and it was collected
by filtration (1HNM" showed 4-80 and something else (discarded)).
The aqueous layer was extracted with AcOEt several times (3-5) and concentrated on
a rotary evaporator under vacuum to afford a solid that was triturated with ether to
afford 5-80 as a bright yellow solid. A total of 117g of desired product was collected
in the first crop (27% yield from diazonium salt). A portion did not crystallize: this
oil was triturated with MeOH and Et2O to afford 3.6g of 5-80; another precipitation
from the mother liquid afforded an additional 6.23g of the desired product 5-80.
Total: 117.0+3.6+6.23 = 126.83. 30.4%). Yield for 3 steps (decomposition of
diazonium salt; deprotection and nitration).
Analytical data from Notebook: 53877-115: 'HNMRCS, MeOD): 8.56-8.27 (dd, J=
7.5, 3.3 Hz, 1H), 8.01 (d, J=3.3 Hz, 1H); LC/MS(M+l)+= 158.9; rt = 0.15 min.
Note: A portion of the aqueous acidic solution was taken and neutralized with
NaaCOs until effervescence stopped and then it was extracted with AcOEt => A
different product was obtained. No desired product in these extracts.
A total of 117g of 5-80 was divided in 4 batches of 30g x 3 and 27g x 1 and treated
with POBrs (3 equiv.; 163g x 3 and 155 g x 1) and a catalytic amount of DMF (15
ml) at rt (DMF was added carefully => gas evolution). After 5 min. at room
temperature, the solutions were heated at 110°C for 3hr. LC/MS showed starting
material had been consumed. The reaction mixtures were allowed to cool to rt. The
reaction flasks were placed in an ice bath; and then ice was added very slowly and
carefully portionwise into the flask, gas evolution was due to HBr formation; the
liquid and black solid that formed was poured into a beaker with ice. EtOAc was
added and the mixture was then extracted several times with EtOAc. The organic
layer was washed with saturated aq. NaHCOs; HaO and brine; dried over Na2SC>4 and
filtered. The product was dried in the pump overnight to provide 123g of 6-80 as a
brown solid (77% yield).
Note: Reaction is completed within Ih.
HNMR(5, CDC13):8.52 (m, IH), 7.93 (m, IH).
800 ml of vinyl magnesium bromide (1M in THF, Aldrich) was cooled below -60°C
with vigorous stirring under N2. 2-bromo-5-fluoro-3-nitro pyridine (43.3g, 0.196 mol)
in 200ml THF was added dropwise via addition funnel at such a rate that the temp
was kept below -60°C. This took ~ 1.25 hr. The reaction mixture was warmed to
-40 to -50°C and stirred for 1 hr more. Then 1L of saturated aqueous NHfCl was
added slowly and cautiously. At first, foaming occurred and considerable solid was
present, but this essentially dissolved as the addition was completed and the material
warmed to rt. The layers were separated and the aqueous layer extracted 3 times with
ethyl acetate. The organic extracts were washed with brine, dried over Na2SO4,
filtered and concentrated to afford ~ 50g of a black gummy solid. HPLC indicated
57-58% product. To this was added CEfoCk and the solid was collected by filtration
and washed with CH2C12 to afford 12.5g of product as a brown solid. The reaction
was repeated on exactly the same scale and worked up in the same manner. From
CH2C12 trituration there was obtained 12.4g of Precursor 2i (H'PLC ~ 97% pure).
The crude was recovered and allowed to stand in dichloromethane. Upon standing
3.6g of additional product separated and was recovered by filtration.
Total yield = 29.5g (35%).
'HNMR(8, CDC13): 8.69(bs, 1H), 7.92 (d, J= 1.8 Hz, 1H), 7.41 (m, 1H), 6.77 (m,lH);
LC/MS(M+1)+=216.-217.9; rt= 1.43 min.
Reaction was carried in a 250ml flask (foaming occurred upon heating and the big
size flask is more convenient). A mixture of precursor 2i (3g, 13.95mmol), 1,2,3-
triazole (15g, 217.6 mmol, 15eq), K2CO3 (1.9g, 13.95mmol, leq) and Cu(0)(0.9g,
13.9mmol, 1 eq) was heated at 160°C for 7 hr (from rt to 160°C total 7 hr) under N2
(depending on the Cu(0) lot, reaction time may vary from 2hr to 7hr). The resulting
mixture was diluted with MeOH, filtered through filter paper (to remove the copper).
Washed with MeOH (20 ml) and water (30 ml).
The filtrate was concentrated (remove solvent in rotovap) and diluted with
ethylacetate. The aqueous layer was extracted with ethylacetate. The combined
organic layer was dried over sodium sulfate, filtered and concentrated. The residue
was dissolved in MeOH (20 ml), 7-80 (750mg) crystallized from the methanol as a
white solid and was collected by filtration. (Slow gradient volume, silica gel hex
AcOEt (0->18%) of the mother liquids usually affords 5-10% more of 7-80.
'HNMR (8, CDC13): 10.47 (bs, 1H), S.76 (s, 1H), 7.94 (s, 1H), 7.89 (s, 1H), 7.53 (m,
1 H), 6.78 (m, 1H); LCMS(M+l)+= 204; rt = 1.29 min.
Ethyl methylimidazolium chloride (4.3g, 29.6 mmol, 3eq) was placed in a 250ml
flask. Aids (11.8g, 88.6mmol, 9eq) was added into the flask in one portion. A
liquid suspension was formed (some of A1C13 remained as solid). After stirring for 5-
10 min. compound (1) (2.0g, 9.85mmol) was added in one portion followed by slow
addition (via a syringe) of ethyl chlorooxalacetate (3.3 ml, 29.6 mmol, 3eq). The
reaction was stirred at room temperature for 20 hr. LCMS indicated compound 8-
80:compound 7-80 = 6:2. (Compound I has strong UV absorption). The reaction was
quenched by carefully adding ice water (~75 ml) at 0°C. A yellow solid precipitated
at this point. The resulting suspension was filtered and the solid was washed with
water. MeOH and ethyl acetate (to remove unreacted SM) and the solid was dried in
air. (LCMS purity 70% ~ 80%) 2g of solid containing 8-80 was obtained and taken
to the next step without further purification. LCMS(M+l)+= 276; it =0.97 min.
A mixture of compound 8-80 (4.9g, 17.8 mmol) & N-benzoylpiperazine
hydrochloride 8a-80 (HC1 salt; 6.0g, 26.7mmol, l.Seq) in DMF (30 ml) was stirred at
overnight (16 hr). A slurry was formed. An additional 20ml of DMF was added
into the slurry. Then HATU (12.2g, 26.7mmol, l.Seq) was added followed by
DMAP (4.3g, 35.6 mmol, 2eq). The reaction mixture was stirred for 30 min. LCMS
indicated the starting material 8-80 was completely converted to product (EXAMPLE
216). The resulting mixture was filtered and the solid washed with water. The
filtrate was concentrated in vacuo. Water was added to the residue and the solid was
collected by filtration. The solids were combined and washed with water, MeOH and
EtOAc. Then the solid was dried in air. LCMS & HPLC showed IVb, >99% pure.
The solid product was further purified by precipitation and crystallization in 5~10%
CH3OH/CHC13.
Purification of IVb
Crude compound IVb obtained as above (15.3g) was dissolved in 10% MeOH/CHCl3
(600 ml). A light brown suspension was formed, filtered through filter paper and
washed with MeOH a twice. The brownish solid was discarded (~1.2g). Compound
IVb was crystallized in the filtrate, the solid was collected by filtration and the white
solid was dried in air. The filtrate was used to repeat the crystallization several times.
The solid obtained from each filtration was analyzed by HPLC. All the pure fractions
were combined. The not so pure fractions were resubjected to crystallization with
MeOH & CHC13. A total of 12.7g of Compound IVb was obtained from
recrystallization and precipitation. The mother liquid was concentrated and purified
on silica gel column (EtOAc, then CHCl3/MeOH (0-2%)) to provide 506mg of
product) as a white solid.
7.4 (bs, 5H), 3.7 (bs, 4H), 3.5 (bs, 4H); MS m/z 448 (MH). Anal: Calc for
C22Hi8FN7O3; C 59.05, H 4.05, N 21.91, F 4.24. Found; C 57.28, H 4.14, N 21.22; F
4.07%.
Examples 1-4:
Preparation ofProdrugs I from Parent Compounds W
Synthetic Scheme for Examples 1-4
Procedure: A suspension of IVa (211 mg, 0.5 mmol) in THF (2 mL; Sure Seal)
under anhydrous N2 atmosphere was treated with NaH (86 mg, 2.2 mmol; 4.4 eq.;
60% oil dispersion). After a few minutes stirring at room temperature, di-tert-butyl
chloromethyl phosphate (782 mg, 3.0 mmol; preparation, see US Patent 6,362,172)
was added and the mixture stirred for 1-5 days, monitoring the completion of the
reaction by HPLC (additional 1-2 eq. of each NaH and the phosphate may be required
to bring the reaction to near completion). After the staring material was consumed,
the mixture was concentrated in vacuo to dryness and the residue, which appeared to
be a mixture of N-alkylated indole mono- and bis-t-butyl phosphate, was dissolved in
CH2Cl2 (5 mL) was treated with TFA (5 mL) at room temperature for 2 h. The
mixture was concentrated in vacuo and the residue was purified by C-18 reverse
phase silica gel, eluting with 5-10% CHaCN in water containing NaHCOs, to obtain
75 rng (0.13 mmol; Y. 26 %) of the title compound la as an off-white powder
(disodium salt): HPLC >99% (AP at 254 nm); LC/MS (ESI+) m/z 533 (M+H minus
2Na)+; HRMS (ESI) m/z calcd for C23H26N409P (M+H minus 2Na)+ 533.1437, found
533.1426 (A -2.1 ppm); !H NMR (D20, 500 MHz) 8ppm 3.51 (2H, m), 3.67 (2H, m),
3.73-3.79 (2H, m), 3.89-3.95 (2H, m), 3.94, 3.95 (3H, 2s), 4.05, 4.07 (3H, 2s), 6.02-
6.04-6.05-6.07 (2H, ABq.), 7.43, 7.44 (1H, 2s), 7.45-7.56 (5H, m), 8.49, 8.52 (1H,
2s).
By using a similar procedure and conditions, Ib was prepared from IVb. Ic and Id
were prepared from IVc, and IVd, respectively, but water rather than sodium
bicarbonate solution was utilized in the purification.
Example 2
Ib: Yield 13 % (disodium salt); HPLC >96% (AP at 254 nm); LC/MS (ESI+) m/z
558 (M+H minus 2Na)+; 1H NMR (D20, 500 MHz) 6ppm 3.59 (2H, m), 3.70-3.84
(4H, m), 3.93-3.95 (2H, m), 5.28-5.29-5.30-5.32 (2H, ABq.), 7.4-7.6 (5H, m), 8.09,
8.10 (1H, 2s), 8.34, 8.36 (1H, 2s), 8.59, 8.61 (1H, 2s), 8.72, 8.75 (1H, 2s).
Example 3
Ic: Yield 37% (acid form. Water was used in place of aqueous sodium bicarbonate
during the purification; HPLC >98% (AP at 254 nm); LC/MS (ESI+) m/z 584
(M+H); 1E NMR (DMSO-d6, 500 MHz) 8ppm 2.40 (3H, s), 3.44 (4H, br.s), 3.66
(4H, brs), 4.04 (3H, s), 5.79 (1H, s), 5.82 (1H, s), 7.46 (5H, brs), 8.07 (1H, s), 8.41
(1H, s), 8.88 (1H, s).
Example 4
Id: Yield 7% (acid form). Water was used in place of aqueous sodium bicarbonate
during the purification; LC/MS (ESI+) m/z 597 (M+H); !H NMR (DMSO-d6, 500
MHz) 5ppm 1.16, 1.21 (3H, 2d, J = 6.5 Hz), 2.29 (3H, s), 2.3-4.5 (7H, m), 4.00, 4.01
(3H, 2s), 5.79-5.85 (2H, m), 6.36 (1H, t, J = 2 Hz), 7.42-7.47 (5H, m), 7.99 (1H, s),
8.08, 8.09 (1H, 2s), 8.34, 8.44 (1H, 2s).
Example 5
General Procedure: A suspension of IVc (0.24 g, 0.5 mmol) in anhydrous THF (4
mL) under nitrogen atmosphere was treated with sodium hydride (60% oil dispersion,
0.08 g, 2.0 mmol), and stirred until gas evolution ceased (approximately 5 minutes).
The reaction mixture was treated with iodine (0.13 g, 0.5 mmol) and stirred for 2-3
minutes followed by addition of di-tert-butyl chloromethyl phosphate (1.6 g, 6.0
mmol, crude). A stream of nitrogen was allowed to pass over the reaction to facilitate
the removal of much or all of the THF. The reaction mixture was stirred overnight.
HPLC analysis of crude indicated starting IVc (ca. 56%) and desired adduct (ca.
32%).
Several crude reaction mixtures (a total of 6.7 mmol based on starting material IVc)
were re-dissolved in dichloromethane, combined, concentrated in vacuo to remove
any remaining THF. The residue was suspended in dichloromethane and TFA (1:1,
approximately 40 mL total volume). The mixture was stirred for 1.5 - 2 hours and
then solvent was removed in vacuo. The residue was suspended in dichloromethane
and extracted into water (approximately 60 mL) made weakly basic with solid or
aqueous sodium bicarbonate. The aqueous layer was reduced in volume by rotary
evaporator if required and the solution was loaded onto a C-18 reverse phase column
(approximately 80 g of C-18, YMC ODS-Aq, 50 micron) and eluted with water,
followed by water containing 2.5% acetonitrile. Fractions containing pure product
were pooled and organic solvent was removed by rotary evaporator. Purified product
was recovered after lyophilization to give 1.00 g (1.30 mmol, 19% over 2 steps) of
the title compound lea (disodium salt) as an off-white powder: HPLC purity >99%
AP at 254 nm (gradient 0-100% B/A; A 10% CH3CN-90% H2O-0.1% TFA, B 90%
CH3CN-10% H2O-0.1% TFA, gradient time'4 min, column YMC ODS-Aq
4.6x50mm 3 micron); MS-ESI- nVz 482 (M-H minus 2Na)~; HUMS (ESI) m/z calcd
for CasBbNyOsP (M+H minus 2Na)+ 584.1659, found 584.1651 (A -1.3 ppm); 'H
NMR (D20, 500 MHz) 5 ppm 2.53, 2.54 (3H, 2s), 3.56 (2H, s, CH2N), 3.72 (2H, br.s,
CH2N), 3.78, 3.83 (2H, 2br.s, CH2N), 3.94, 3.96 (2H, 2br.s, CH2N), 4.14 (3H, s,
CH3O), 5.38, 5.40 (2H, 2d, J=llHz), 7.45-7.59 (5H, m, Ar-Hs), 8.07, 8.09 (1H, 2s,
indole-H-5), 8.64, 8.67 (1H, 2s, indole-H-2), 8.87, 8.89 (1H, 2s, triazole-H-5); ,13CNMR
(125.7MHz, D2O) 5 ppm 15.43 (N-Me), 44.03,44.47, 44.66, 45.05,48.20,
48.82, 49.60, 50.23, 59.78 (OMe), 75.81 (NCH20), 115.6, 126.0, 127.2,129.6,131.0,
131.7, 132.1, 133.5, 136.8, 147.6, 150.1,154.2,164.8,170.4, 175.8, 189.2; UV
(H20) Amax 220 nm (e 3.91xl04), 249 nm (e 2.00xl04), 303 nm (e 1.60xl04); Anal:
Calc for C25H24N708PNa2. 8H2O. 0.2NaHC03; C 38.39, H 5.14, N 12.44, P 3.93, Na
6.42 Found; C 38.16, H 4.81, N 12.43, P 3.72, Na 6.05; KF (H2O) 17.3%.
A less pure fractions were collected to obtain 0.22 g (0.29 mmol, Y. 4%) of the title
compound lea (disodium salt): HPLC purity 95% (AP at 254nm).
Example 6
Phosphate ester A (45.lg, O.lmol) and chloroiodomethane B (200g, 1.14mol)
were combined in 100ml of benzene and the mixture was stirred at room temperature
for four hours before benzene was removed under vacuum. Then, 500ml of ethyl
ether was added to the residue and insoluble solid was filtered away. Concentration
of the filtrate provided di-tert-butyl chloromethyl phosphate, which was utilized in
the next step without any purification.
NaH (2.4g, 60% in oil) was added slowly into a suspension of IVa in dry THF
(120ml) and the mixture was allowed to stir for an hour at room temperature. Iodine
(5g) dissolved in dry THF (10ml) was added slowly into the stirring solution.
Following completion of addition the resultant mixture was stirred at ambient
temperature for an additional 15 minutes and then compound di-tert-butyl
chloromethyl phosphate, obtained from step one, was added. After stirring for 16
hours, the reaction mixture was poured into ice water (120ml), followed by extraction
with EtOAc (3 x 300ml). The combined organic extracts were washed with water
(100 ml) and then brine (100ml), dried over Na2SC4, and concentrated under vacuum
to afford a residue, which was purified by silica gel chromatography (elution with
EtOAc/Et3N (100/1) and then EtOAc/MeOH (100/1)) to give diester Ila in yields of
70 - 80%.
A mixed solution of TFA (50ml) and dichloromethane (450ml) was added
into a round bottom flask containing 43.3g of diester Ila. After stirring at room
temperature for 16 hours, the reaction mixture was concentrated under vaccum to
offer a residue of lac which was used in further steps without any purification.
The above 55g crude product lac was added to an aqueous solution of L-lysine
(1.36M, 70 mL) at room temperature. The resulting suspension (pH^l.83) was added
to a lysine solution (1.36 M, -40 mL) to pH 4.88. The resulting suspension was
filtered through a pad of Celite. The clear light yellow filtrate (-200 mL) was mixed
with acetone (200 mL) and heated to 45 °C. Acetone (1400 mL) was added over 2h at 45 °C. The clear solution was seeded and stirred at 45 °C for 2h, and slowly cooled
to room temperature (5h) and the suspension stirred overnight. The white solid was
collected by filtration and dried under house vac. at 50 °C over 24 h to afford 41.2 g
of lab as an off-white solid.
The above solid was dissolved in 1:1 water-acetone (560 mL) at 45 °C. Acetone (700
mL) was added over a period of Ih at 45 °C. The clear solution was seeded and
stirred at 45 °C for 2h. Slowly cooled to room temperature (5h) and the suspension
stirred at room temperature overnight. The white solid was collected by filtration and
dried under house vac. at 50 °C over 36 h to afford 33 g of lab as an off-white solid.
The AP was >99% by HPLC.
'HNMR (500 MHz, D2O) £8.42 (s, 1/2H), 8.39 (s, 1/2H), 7.52 (m, 6H), 6.12 (m,
2H), 4.07 (s, 3H), 3.93 (m, 5H), 3.72 (m, 3H), 3.67 (m, 2H), 3.52 (m, 2H), 3.05 (m,
2H), 1.93 (m, 2H), 1.74 (m, 2H), 1.50 (m, 2H); MS m/z: (M+H-lysine)+ calcd for
C23H26N4O9P 533.14, found 533.03. M.P. 166.7 to 172.2 degrees. Using
comparative IH NMR integration of several different peaks, the ratio of lysine to IVa
is calculated to range from 1.05 : 1 to 1.2 : 1 equivalents of lysine to parent prodrag.
The salt form was determined to be a hydrate. Based on DSC (diffraction scanning
calorimetry) and TGA (thermal gravity analysis), the observed water content is
2.80%. Theoretical calculation for a monohydrate is 2.58%. Thus, the ratio of water
to parent molecule in the hydrate could be in the range 1 : 1 to - 1.5 : 1.
Example 7
Preparation of crystalline Ic (free acid mono-hydrate)
To a mixture of IVc (600 mg, 1.27 mmol) in anhydrous THF (10 ml) in an
oven-dried round bottle flask under nitrogen at r.t. was added NaH (153 mg, 6.38
mmol., dry powder, 95%), and the white suspension stirred until no gas evolution was
observed. The mixture was then added I2 (375 ing, 1.48 mmol), and stirred at r.t. for
3 h. To the reaction mixture was added NaH (153 mg, 6.38 mmol, dry powder, 95%),
and the mixture stirred for about 5 to 10 min. The crude chloromethyl di-tertbutylphosphate
(2.0 g, about 1.6 ml, 7.79 mmol) was added to the mixture, which
was then stirred at r.t. for 15 h. LCMS analysis of the reaction showed a >97%
conversion of the starting material. After evaporation of the volatiles, the residue was
added CH2C12 (10 ml), cooled in an ice-water bath, slowly added TFA (10 ml) and
stirred at r.t. for 3 h. The reaction mixture was then evaporated, and the residue
partitioned between CHaCla (50 ml) and H2O (50 ml). The CH2C12 layer was poured
into the reaction flask that contained some undissolved brownish solid, and this
mixture was extracted with a dilute aqueous NaHCOs solution (50 rnl). The aqueous
mixture was purified by reverse phase preparative HPLC (solvent A: 10% MeOH—
90% H2O-0.1%TFA; solvent B: 90% MeOH-10% H2O-0.1%TFA; start %B = 0,
final %B = 100; gradient time = 6 min; flow rate = 45 ml/min; column: phenomenex-
Luna 30 x 50 mm, S5; fraction collected: 3.65 to 4.05 min). The fractions collected
were evaporated to dryness, and the residue dried under high vacuum to obtain the
acid Ic as a pale yellow solid (356.6 mg); 1R NMR: (500 MHz, CD3OD) 5 9.05 (s,
1H), 8.46 (s, 1H,), 8.04 (s, 1H), 7.47 (b s, 5H), 5.93 (d, J- 12, 2H), 4.10 (s, 3H),
4.00-3.40 (b s, SH), 2.53 (s, 3H); 19F NMR analysis showed that the material
contained residual TFA, (the percentage was not quantified); Analytical HPLC
method: Start %B = 0, Final %B = 100, Gradient time = 2min, Flow Rate = 5mL/niin,
Column: XterraMS CIS 7u 3.0x50mm, LCMS: (ES+) m/z (M+H)+ = 584, HPLC Rt
= 0.983.
172.2 mg of the purified acid Ic was dissolved in 1 ml of H2O and then about
0.3 ml of absolute EtOH (200 proof) was added. The mixture was left standing in a
refrigerator (temperature about 3°C) overnight, after which time, crystalline material
was observed. The mixture was then warmed to ambient temperature, diluted with
H2O to a volumn of 3 mL, and then 20 mL of MeCN was added slowly. Following
the completion of addition, the mixture was stirred at r.t. for 2 h and then filtered.
The solid collected (90 mg) was dried in vacua, and then tinder high vacuum. This
material was shown by powder x-ray studies to be crystalline; Elemental Analysis
calculated for OzsIfceNyOgP-EkO: C 49.92; H 4.69; N 16.30; observed: C 49.66; H
4.62; N 15.99; mp = 205°C (measured by differential scanning calorimetry). The IH
NMR pattern for crystalline material was compared with that from the purified acid
and both were consistent with the structure.
Example 8
Preparation of lab (mono L Lysine salt): {3-[(4-benzoylpiperazin-l~yl)(oxo)acetyl]-
4,7-dimethoxy-lH-pyrrolo[2,3-c]pyridin-l-yl}methyl dihydrogen phosphate, L-lysine
salt (1:1). The sequence of reactions is described in Scheme for Example 8.
The tetrabutylammonium salt of bis-tert butyl phosphate (45. Ig, O.lmol) and
chloroiodomethane (200g, 1.14mol) were combined in 100ml of benzene and the
mixture was stirred at room temperature for four hours and then the benzene was
removed under vacuum. A portion of 500ml of ethyl ether was added to the residue
and insoluble solid was filtered away. Concentration of the filtrate in vacuo and
removal of the volitiles on a vacuum pump provided di-tert-butyl chloromethyl
phosphate, as a light yellow or light brown oil which was utilized in the next step
without further purification.
Preparation oflla: (3-(2-(4-benzoylpiperazin-l-yl)-2-oxoacetyl)-4,7-dimethoxy-lHpyrrolo
[2,3-c]pyridin-l-yl)methyl di-tert-butyl phosphate
NaH (2.4g, 60 mmol, 60% in oil) was added slowly to a suspension of (8.4g,
20 mmol) IVa in dry THF (120ml) and the mixture was allowed to stir for an hour at
room temperature. Iodine (5g, 20mmol) dissolved in dry THF (10ml) was added
slowly and cautiously to the stirring solution at a rate to keep foaming under control.
Following completion of addition, the resultant mixture was stirred at ambient
temperature for an additional 15 minutes and then the ~0.1 mol di-tert-butyl
chloromethyl phosphate, obtained as described in step one, was added. After stirring
for 16 hours, the reaction mixture was poured into iced NEUOAc (30%) (120ml),
followed by extraction with EtOAc (3 x 300ml). The combined organic extracts were
washed with water (100 ml) and then brine (100ml), dried over Na2SO4, and
concentrated invacuo to afford a residue, which was purified by silica gel
chromatography (elution with EtOAc/Et3N (100/1) and then EtOAc/MeOH (100/1) to
give diester Ha (9.0-10.3gs, AP -75%) as a light yellow solid in yields of 70 - 80%
over several runs.
JH NMR (500 MHz, CDC13) = 11.5 Hz), 4.05 (s, 3H), 3.90 (s, 3H), 3.90 - 3.30 (b, 8H), 1.39 (s, 18H); 13CNMR
(125MHz, CDC13) (5185.5, 170.7, 166.5, 146.9, 146.2, 139.6, 135.3, 130.2, 128.7,
128.4, 127.2, 124.5,122.0, 120.8, 115.8, 83.8, 73.2, 57.3, 53.5, 46.1, 41.7, 29.8; MS
m/z: (M+H)+ calcd for C3iH42N4O9P 645.27, found 645.10.
Preparation of lab: {3-[(4-benzoylpiperazin-l-yl)(oxo)acetyl]-4,7-dimethoxy-lHpyrrolo[
2,3-c]pyridin-l-yl}methyl dihydrogen phosphate, L-lysine salt (1:1)
500mg of diester Ha was dissolved in a mixture of water (3 ml) and acetone (3 ml).
The resulting mixture was stirred at 40°C for 16 hours to allow the solvolysis to
reach completion. To this reaction mixture (-69 AP) was added 4M aqueous lysine
solution to adjust pH to 4.83. Acetone (35 ml) was slowly added into the reaction
mixture in 30 min at 45 - 50°C. At 45°C, the clear solution was seeded with
crystalline lab and kept stirred at this temperature for 45 min. After complete
addition of acetone, the solution was cooled to room temperature in 4 hours and the
crystallization of lab completed overnight. The solid was collected by filtration and
suction under nitrogen for 2 hours. The white crystalline solid was dried under house
vacuum at 50 - 55°C for 24 h to afford 343 mg of lab.
lab obtained in the above operation: 1R NMR (500 MHz, CD3OD) (m, 6H), 6.13 (d, 2H, J= 10.5 Hz), 4.06 (s, 3H), 3.92 (s, 3H), 4.00 - 3.40 (m, 8H),
3.58 (t, 1H, J- 6 Hz), 2.92 (t, 2H, J- 7.5 Hz), 1.90 -1.40 (m, 6H); 13C NMR (125
MHz, CD3OD) 127. 2, 124.6, 122.3, 120.2,114.6, 73.2, 56.6, 54.7, 53.1, 46.0, 41.6, 39.2, 30.5, 27.0,
22.0. HRMS m/z: (M-lysine+H)+ calcd for CasHaeN^P 533.1437, found 533.1437.
Anal. Calcd. C, 51.32; H, 5.79; N, 12.38; P, 4.56; found: C, 48.54; H, 5.32; N, 11.76;
P, 4.04. Melting Point 170°C.
Obtained via other process (hydrolysis with TFA hi methylene chloride), lab was a
1.70 molar hydrate and 1.14 molar lysine salt. JH NMR (500 MHz, D20, 60°C)
(58.72 (s, 1H), 7.84 (m, 6H), 6.44 (d, 2H, J- lOHz), 4.41 (s, 3H), 4.27 (s, 3H), 4.3 -
3.7 (m, 8H), 4.10 (t, 1H, J= 5Hz), 3.39 (t, 2H, J- 5Hz), 2.30 - 1.80 (m, 6H); 13C
NMR (125 MHz, D2O, 27°C) £186.7, 174.9, 173.2,167.9, 147.7, 145.7,142.6,
134.3, 131.1, 129.2, 127.1,124.3,122.4,120.1, 113.8, 73.5, 57.1, 54.9, 54.4, 47.7,
47.1, 46.3, 45.7, 42.6, 42.1, 42.0, 41.5, 39.5, 30.2, 26.8, 21.8 . HRMS mlz: (Mlysine+
H)+ calcd for CssH^OgP 533.1437, found 533.1425. Anal. Calcd. C, 49.11;
H 6.13; N, 12.05; found: C, 48.93; H 6.26; N 12.07. M.P. 168 - 172°C.
Example 9
Preparation ofibb (mono L Lysine salt): [3-[(4~benzoylpiperazin-l-yl)(oxo)acetyl]-
4-fluoro- 7-(lH-l,2,3-triazol-l-yl)-lH-pyrrolo[2,3-c]pyridin-l-yl] methyl dihydrogen
phosphate, L-lysine salt (1:1). The sequence of reactions is described in the Scheme
for Example 9.
The tetrabutylammonium salt of bis-tert butyl phosphate (57'g, 0.126 mol,
Digital Specialty Chemicals) and chloroiodometllane (22Ig, 1.26mol) were stirred at
room temperature for four hours and then the volatiles were removed in vacuo.
500ml of ethyl ether was added to the residue and insoluble solid was filtered away.
Concentration of the filtrate and final removal of volatiles using a vacuum pump
provided di-tert-butyl chloromethyl phosphate (112g), typically as a light yellow or
brown oil, which was utilized in the next step without any further purification.
Preparation of lib: (3-(2-(4-benzoylpiperazin-l-yl)-2-oxoacetyl)-4-fluoro- 7-(lH-
1,2,3-triazol-l-yl)-lH-pyrrolo[2,3-c]pyridin-l-yl)methyl di-tert-butyl phosphate
lib
NaH (5.65g, 95% dispersion in mineral oil, 0.224 mol) was added slowly into
a suspension of IVb (20g, 44.7 mmol) in dry THF (400ml) and the mixture was
allowed to stir for 0.5 hour at room temperature. A solution of iodine (11.3g, 44.5
mmol) dissolved in dry THF (20ml) was added slowly into the stirring solution at a
rate which kept the reaction from becoming violent. The resultant mixture was
stirred for an additional 3 hours before a second portion of 95% NaH (5.65g,
0.224mol) was introduced. After 1 5 minutes at ambient temperature, di-tert-butyl
chloromethyl phosphate, (1 12g), obtained from step one, was added in one portion.
After stirring for 16 hours at ambient temperature, the reaction mixture was poured
into iced NH4OAc (30%) (200ml) and then extracted with EtOAc (3 x 500ml). The
combined organic extracts were washed with water (200ml) and then brine (200ml),
dried over NaaSO^ and concentrated under vacuum to afford a residue, which was
purified by silica gel chromatography (elution with EtOAc/MeOH/EtaN (100/1/1) to
give IS.Ogs (43% yield corrected for 85% AP) of diester lib as a light yellow solid.
'HNMR (500 MHz, CDC13) 7.41 (b, 5H), 5.90 (d, 2H,/= 14.5Hz), 3.90 - 3.40 (b, 8H), 1.23 (s, 18H); 13C NMR
(125 MHz, CDC13) (5182.9, 170.7, 165.1, 154.6, 152.5, 144.1, 135.1, 134.0, 131.9,
130.3, 128.7, 128.3, 127.2, 125.9, 124.3, 114.0, 84.1, 74.1, 46.2, 41.9, 29.6; HRMS
mlz: (M+H)+ calcd for C31H38FN707P 670.26, found 670.34.
Preparation oflbb (mono LLysinesalt): [3-[(4-benzoylpiperazin-l-yl)(oxo)acetyl]-
4~fluoro-7-(lH-l12,3~t)iazol-l-yl)-lH-pyrrolo[2,3-c]pyridin~l-yl]metl'tyl dihydrogen
phosphate, L-lysine salt (1:1)
Diester lib (27g) was dissolved in a mixture of water (55ml) and acetone (55ml). The
resulting mixture (pH: not determined) was stirred at 40°C for 16 hours to complete
the solvolysis. To this reaction mixture was added 4M aqueous lysine solution to
adjust pH to 3.51. EtOH (500 ml) was added into the solution and the flask wall was
coated with some product after overnight. The clear solution was then transferred to
another flask and EtOH (1500 ml) was slowly added to the reaction mixture in ~ 3h.
After complete addition of ethanol, the solution was stirred at room temperature for
48 hours and the resultant solid (Ibb) was collected by filtration and rinsed with
ethanol. The white crystalline solid was dried under house vacuum at 55°C for 24 h
to afford 10.92 g of Ibb (98 AP).
This solid was futher mixed with 12.5g of salt obtained from other operations in 70
ml of water. EtOH (1000 ml) was then added and the resultant solution was stirred at
r.t. for over 20 hours. The solid was collected by filtration, rinsed with EtOH (2 x 80
ml) and dried under house vaccum at 50 C under nitrogen atomosphere for 44 hours
to afford 21.5 g of Ibb in AP of 98.7.
Ibb obtained in the above procedure was ~1 molar lysine salt with 1.12% of water,
0.8% of TFA and 0.05% of ethanol. JH NMR (500 MHz, CD3OD, 50°C) $.94 (s,
1H), 8.87 (s, 1H), 8.69 (s, 1H), 8.42 (s, 1H), 7.83 (m, 5H), 5.81 (d, 2H, J= 12.5Hz),
4.30 - 3.70 (m, 8H), 4.08 (t, 1H, J= 6.5Hz), 3.67 (t, 2H, J= lOHz), 2.26 (m, 2H),
2.07 (m, 2H), 1.88 (m, 2H); 13C NMR (125 MHz, D2O, 30°C) 166.8, 153.1, 146.8, 134.8, 134.3, 131.3,131.1,130.3, 129.3, 128.9,128.7, 128.5,
127.2, 124.2, 112.6, 74.0, 54.9, 47.9, 47.2, 46.4, 45.9, 42.7, 42.2, 42.0,41.7, 39.5,
30.3, 26.8, 21.8. MS m/z: (M-lysine+H)+ calcd for CasfibaFtyOyP 558.1302, found
558.1293. Anal. Calcd. C, 48.75; H, 5.07; N, 17.63; P, 4.33; found: C, 49.02; H 4.90;
N, 17.90; P, 4.37. M.P. 193°C. pKa (potentiometric) 6.1, 9.1.
Example 10
Preparation oflcb (mono tromethamine salt): [3-[(4-benzoylpiperazin-lyl)(
oxo)acetyl]-4-methoxy-7-(3-methyl-lH-l,2,4-ti'iazol-l-yl)-lH-pyrrolo[2,3-
c]pyridin-l-yl]methyl dihydrogen phosphate, 2-amino-2-(Jiydroxymethyl)propane-
1,3-diol salt (1:1). The sequence of reactions is described in Scheme for Example 10.
A mixture of tetrabutylammonium di-tert-butyl phosphate (51'g, 0.126mol,
Digital Specialty Chemicals) and chloroiodomethane (22 Ig, 1.26mol) was stirred at
room temperature for four hours before the volatiles were removed under vacuum.
500ml of ethyl ether was added to the residue and insoluble solid was filtered away.
Concentration of the filtrate in vacuo and removal of remaining volatiles using a
vacuum pump provided di-tert-butyl chloromethyl phosphate as a light brown or
yellow oil, which was utilized in the next step without further purification.
Preparation of He: (3-(2-(4-benzoylpiperazin-l-yl)-2-oxoacetyl)-4-methoxy-7-(3-
methyl-lH-1,2,4-triazol-l-yl)-lH-pyrrolo [2,3-c]pyridin-l-yl)methyl di-tert-butyl
phosphate
NaH (2.6g, 10.3 mmol, 95% in oil, 5eq.) was added slowly into a suspension
of IVc (lO.Og, 21.1 mmol) in dry THF (100ml) and the mixture was allowed to stir
for 0.5 hour at room temperature. A solution of iodine (5.27g, 20.8 mmol) dissolved
in dry THF (10ml) was added slowly into the stirring solution at a rate which
prevented foaming or a violent reaction. The resultant mixture was stirred for an
additional 3 hours before a second 2.6g portion of NaH was introduced. After 15
minutes at ambient temperature di-tert-butyl chloromethyl phosphate, the entire batch
of di-tert-butyl chloromethyl phosphate, obtained from step one, was added. After
stirring for 16 hours, the reaction mixture was poured into iced NELjOAc (30%)
(120ml), followed by extraction with EtOAc (3 x 300ml). The combined organic
extracts were washed with water (100 ml) and then brine (100ml), dried over NaaSQi,
and concentrated under vacuum to afford a residue, which was purified by silica gel
chrornatography (elution with EtOAc/Et3N (50/1) and then EtOAc/MeOH (100/1)) to
give 8.0g (-75% AP, -41% yield)- of diester He as a light yellow solid.
'HNMR (500 MHz, CD3OD) (58.82 (s, 1H), 8.41 (s, 1H), 8.04 (s, 1H), 7.47 (b, 5H),
6.00 (d, 2H, J- 14.5Hz), 4.10 (s, 3H), 4.00 - 3.40 (b, 8H), 2.49 (s, 3H), 1.28 (s, 18H);
13CNMR(125 MHz, CD3OD) 518.6, 176.4, 172.9, 168.0, 162.6, 152.6, 147.5, 144.0,
136.5, 131.5, 130.8, 129.9, 129.1, 128.3, 126.1, 124.0, 116.2, 85.8, 75.4, 61.6, 57.7,
30.1, 22.2, 13.7; HRMS m/z: (M+H)+ calcd for Css^NyOgP 696.29, found 696.34.
Preparation oflcb (mono L tromethamine salt): [3-[(4-benzoylpiperazin-lyl)(
oxo)acetyl]-4-methoxy-7-(3-methyl-lH-l,2,4-ti-iazol-l-yl)-lH-pyrrolo[2,3-
c] pyridin-1-yl] methyl dihydrogen phosphate, 2-amino-2-(hydroxymethyl)propane-
1,3-diol salt (1:1)
Icb
500mg (~75 AP, 0.54 mmol) of diester He was dissolved in a mixture of water (2.5
ml) and acetone (2.5 ml). The resulting mixture was stirred at 40°C for 16 hours to
complete the solvolysis. To this reaction mixture was added 3.0M aqueous TRIS
(mono tromethamine) solution to adjust pH to 3.32. Acetone (30 ml) was slowly
added to the reaction mixture in 1 hour. After complete addition of acetone, the
solution was stirred overnight to complete the crystallization oflcb. The solid was
collected by filtration and rinsed with 20:1 acetone-water (2x5 mL). The white
crystalline solid was dried under house vacuum under nitrogen atomosphere at 50°C
for 24h to afford 290 mg of Icb (>98.5 AP).
After adding about 15 and 20 ml of acetone, the reaction mixture was seeded with
crystalline Icb.
Icb obtained in the above operation: !H NMR (500 MHz, CD3OD) $.83 (s, 1H), 8.52
(s, 1H), 8.02 (s, 1H) 7.49 (b, 5H), 5.469 (d, 2H, /= 13 Hz), 4.11 (s, 3H), 4.00 - 3.40
(m, 8H), 3.66 (s, 6H), 2.50 (s, 3H); 13C NMR (125 MHz, CD3OD) £185.6,171.9,
167.4, 161.4, 151.7, 146.9, 143.8, 135.4, 130.3, 129.7, 128.8, 127.2, 124.9, 122.6,
114.3, 73.5, 61.8, 59.9, 56,5, 46.0, 41.7, 12.6. HRMS mlz: (M-trisamine+H)+ calcd
for C25H27N7O8P 584.1659, found 584.1664. Anal. Calcd. C, 49.43; H, 5.29; N,
15.90; P, 4.39; found: C, 49.18; H, 5.38; N, 15.59; P, 4.26. Melting Point 203°C.
Obtained via other process (hydrolysis with TFA in methylene chloride), salt Icb is
~lmolar mono tromethamine salt with 0.47% of water, 0.1% of acetone and 0.05% of
methanol. 1E NMR (500 MHz, d6-DMSO, 30°C) 1H) 7.44 (b, 5H), 5.42 (d, 2H, J = 15Hz), 4.02 (s, 3H), 3.70 - 3.30 (m, 8H), 3.41 (s,
6H), 2.38 (s, 3H); 13CNMR (125 MHz, CDC13, 30°C) £184.8, 169.0,165.8, 160.3,
150.4, 146.2,143.2, 135.4,129.4,128.9, 128.2, 127.7, 126.9, 123.2, 122.2,112.9,
72.3, 60.7, 59.0, 56.7, 13.4. MS mlz: (M-trisamine+H)+ calcd for C^vNyOsP
584.2, found 584.0. Anal. Calcd. C, 49.11; H, 5.37; N, 15.76; P, 4.32; found: C,
48.88; H 5.28; N, 15.71; P, 4.16. M.P. 201 - 205°C.
General Procedure to Form Additional Salts of lac
1.2 eq. of metal alkoxide was added into a solution of phosphoric acid in THF
and precipitate was collected as salt form.
Procedure B:
2.2 eq. (for Na, K) or 1.2 eq. (for Mg) of metal alkoxide was added into a
solution of phosphoric acid in THF. After 2 hours, solvent was evaporated and
MeOH was added to provide a clear solution. EtOH or iPrOH was then added into
the solution until it became cloudy. Then, MeOH was added cautiously to let
solution become just clear again. The mixed solution was left open to air for 16
hours and resultant precipitate was collected as the salt form.
Procedure C:
2.2 eq. of amine was added into a solution of phosphoric acid in THF. After 2
hours, solvent was evaporated and MeOH was added to provide a clear solution.
EtOH or iPrOH was then added into the solution until it became cloudy. Then,
MeOH was added cautiously to let solution become just clear again. The mixed
solution was left open to air for 16 hours and resultant precipitate was collected as
salt form.
Di-phosphate ester Ha (500mg) was dissolved in 5ml of 10% TFA in THF.
The reaction mixture was stirred at room temperature for 4 hours before being
quenched by 10% aqueous NaaCOs solution (30ml). After being washed with EtOAc
(50ml), the aqueous phase was concentrated under vacuum to provide a residue
which was purified using Shimadzu automated preparative HPLC System to afford
the desired mono-phosphate E'a (26.5mg) ). 1R NMR (500 MHz, CDC13) d 8.13 (s,
1H), 7.40 (b, 6H), 6.13 (d, 2H, J = 1 1.5Hz), 4.05 (s, 3H), 3.88 (s, 3H), 3.90 - 3.40 (m,
8H), 1.39 (s, 9H); MS m/z: (M+H)+ calcd for C27H34N4O9P 589.21, found 589.13;
LC retention time 1.32min (column: Xterra 4.6x50mmC18 Sum).
To the inerted reactor, di-tert-butyl potassium phosphate (1.69 kg), 4.0 eq. of
sodium carbonate and 0.05 eq of tetrabutyl arnmom'um hydrogen sulfate were added
through the manway. Methylene chloride(7.7 L/kg) was then pumped through the
sprayball to wash down the reactor walls. With the jacket temperature below 10 °C,
the exothermic water charge was added over the course often minutes (7.6 L/kg).
The associated exotherm was minor with a batch temperature rising from 1 1.1 to 16.2
°C over the course of the addition. With the jacket and batch temperature near 7 and
15 °C, respectively, 2.0 eq. of chloromethylsulfonylchloride (CMCS) was charged via
addition runnel. The charge continued for 2 hours while the jacket temperature was
slowly raised to 20 °C during the charge. The maximum batch temperature during the
CMCS charge was 25.3 °C. The jacket temperature was slowly raised during the
charge to ensure that the exotherm started as preliminary laboratory data indicated
that the exotherm may be slowed at lower batch temperatures. The reaction mixture
was agitated and after 3.5 hours, an NMR sample indicated that the reaction had
progressed 72%. The reaction was allowed to proceed overnight with a batch
temperature between 19.7 and 23.6 °C (Delta V historian). An NMR sample taken
after 16 hours indicated a reaction conversion of 76%. Laboratory batches ranged in
conversion from 60 to 80%.
Work-up
After the reaction was deemed complete, additional water at 9.3 L/kg was
added to the batch to affect a phase split. The product rich lower phase was
transferred to a carboy and the upper aqueous phase was sent to waste. A small rag
layer was kept with the product rich organic. The organic phase was returned to R-
1A and additional water at 5.1 L/kg was added as a wash. The phases were split with
the product rich organic, approximately 18.5 kg, being sent to a carboy while the
upper aqueous phase was sent to waste. No rag layer or solids were observed in the
second split. However, it is recommended to polish filter the product rich organic to
remove precipitated salts.
Methylene Chloride Distillation
The product rich organic was transferred to the rotovap bowl of EVAPO-1 A.
Distillation of the methylene chloride was initiated with a jacket temperature of
approximately 22 °C. The distillation rate slowed after 4.5 hours and a batch sample
was taken to analyze the methylene chloride content. NMR analysis indicated a 4:1
ratio of di-tert-butyl chloromethyl phosphate to methylene chloride. Typical
laboratory results of this stream would indicate a 10:1 ratio so the distillation was
continued with an increase in the rotovap jacket temperature. After an additional 2.5
hours, the distillation rate stopped. An NMR sample of the batch indicated that the
ratio had increased to 5:1 di-tert-butyl chloromethyl phosphate to methylene chloride.
The maximum rotovap jacket temperature was 28.4 °C.
Purity of the di-tert-butyl chloromethyl phosphate oil
NMR analysis of the di-tert-butyl chloromethyl phosphate oil indicated the
potency to be greater than 100%. Development work typically produced material
with a potency of 100 + 10%. Karl-Fischer analysis measured water content at 0.02
wt% and GC analysis measured methylene chloride at 10.69 wt%. Thus, the reported
potency is 89.29 wt% accounting for the methylene chloride and water contribution in
the oil.
Storage of di-tert-butyl chloromethylphosphate
The di-tert-butyl chloromethyl phosphate oil was placed in cold room and the
temperature was monitored with a stripchart recorder. Laboratory batches were
typically held between 0 to 5 °C. An NMR of the product after the 104 hour hold in
the cold room indicated that the material had not lost potency.
(Safety testing conducted during the campaign indicates that upon holding the oil
self-heats with a subsequent pressure build-up).
NMR Standard Prep and Sample Prep
Preparation of trimethylphosphate (TMPO standard solution:
A standard solution of TMP04 should be prepared based on a 100 M%
theoretical yield. For example: a 10 g input of the di-t-butyl potassium phosphate
salt should yield 10.41 g (0.402 mols) of di-tert-butyl chloromethyl phosphate. The
volume of dichloromethane in the reaction mixture will be 75 niL. The molarity of
the solution is 0.536. A TMP04 solution should be prepared in that molarity and 0.5
mL of that solution should be combined with 0.5 mL of the dichloromethane layer
from the reaction. The integrals found in the 31P NMR can be directly compared and
will give the % conversion of di-tert-butyl chloromethyl phosphate.
Determination of% unreacted starting material in the reaction aqueous phase:
After recording the volume of the reaction aqueous phase, accurately transfer
0.500 mL into a 1-dram vial containing a known weight of internal standard TMP04-
Add approximately 0.24 mL of D20. Shake to mix thoroughly. Obtain 31P-quant
spectra.
Calculation % unreacted starting material:
sp.
aq.
vol.
act.
inpt.
mg
TMP04
A vol.
sample
(0.5 mL)
248.30
MWst.
mat.
X 140.08
MW
TMPO4
31P NMR
integration st.
mat.
integration
TMP04
10
0
" 10
unreacted
starting
material in
the rxn. aq.
Example:
212
mL
11.0
13.4 mg
0.500 mL
248.30
MWst.
mat.
140.08
MW
TMPO4
9.617
3.26%
Determination of the %-potency of the product oil:
After recording the net weight of the distilled product oil, tare a 1-dram,
screw-top vial containing a known weight of internal standard TMPO4. Transfer
approximately 0.02 mL of product oil into the vial and record the net weight of
product oil. Add approximately 0.7 mL of CDCls. Shake to mix thoroughly. Obtain
31P-quant spectra. Inspect the !H NMR spectra for the presence of residual phasetransfer
catalyst (tetra-n-butyl-ammonium bisulfate) and methylene chloride. Report
these as mol% relative to product.
Calculation of %-potency:
mg
TMPO4
mg sample
258.68 MW
product
X 140.08 MW
TMPO4
31T-r NMR
integration product
31PNMR
integration TMP04
x 100 =
% potency
(w/w) of the
product oil
Example:
13.7 mg
TMPO4
22.3 mg
sample
258.68 MW
product
A 140.08 MW
TMP04
44.744
x 100
55.256
91.9%
potency
(w/w) of the
product oil
NMR Data for di-tert-butyl chloromethyl phosphate
'HNMR (300.13 MHz, CDC13): 5 1.52 (s, ISH), 5 5.67 (d, J= 15.5, 2H)
13C NMR (75.47 MHz, CDC13): 5 29.77 (d, J= 4.5, 6C), 5 73.34 (d, J= 7.5,1C), 5
84.16(d,J=1.5,2C)
31P NMR (121.49 MHz, CDC13): 5 -10.51 (s, IP)
A 500 ml 4-neck round bottom flask equipped with an overhead stirrer,
thermocouple, addition funnel, a nitrogen inlet and a septa was charged IVa (20.01 g,
47.37 mmol), K2C03 (13.13 g, 95.00 mmol) and DMSO (100 ml, 1.41 moles) and the
reaction was stirred at room temperature resulting in a light brown heterogeneous
suspension. Di-tert-butyl chloromethyl phosphate (14.83 g, 57.32 mmol) was added
via addition funnel and the reaction was heated to 30 °C for 16-24 hours after which
time the reaction was cooled to 10 °C. To the reaction was added DCM (200ml) then
was slowly quenched with water (200 ml) maintaining the reaction temperature under
20 °C resulting in a biphasic mixture. The product rich bottom layer was separated,
washed with water (200ml), then transferred to a 500ml 4-neck round bottom flask
equipped with an overhead stirrer, thermocouple, addition funnel, and nitrogen inlet.
Trifluoroacetic acid (53.0 ml, 700.94 mmol) was added via addition funnel resulting
in a slight exotherm. The reaction was stirred for 1-3 hours then cooled to 0 °C.
Methanol (300ml) was added keeping the reaction temperature under 20 °C, and then
the cooled to 0 °C. The reaction flask was fitted with a distillation apparatus and
concentrated under vacuum to a volume of 200 ml (200 torr, was seeded with lac (0.200 g) then stirred overnight at room temperature resulting in
a slurry. The slurry was filtered then the wet cake was washed with THF (300ml)
then dried in a vacuum oven at 50 °C overnight resulting in a pale yellow to white
powder (23.94g, 95%). !H NMR (400 MHz, DMSO-d6) 6 8.30 (s, 1H), 7.55 (s, 1H),
7.44 (s, 5H), 6.12 (d, /= 10.6 Hz, 2H), 3.97 (s, 3H), 3.85 (s, 3H), 3.80-3.22 (m, 8H);
13C NMR (100 MHz, DMSO-d6) 6 185.49, 169.26,166.06, 146.20,145.60, 140.64,
135.50,129.68, 128.41, 127.04,123.46,121.17, 120.08,114.32, 72.43, 56.92, 53.32,
45.22, 40.50; ES+ MS m/z (rel. intensity) 533(MH+, 100), 453(MH+ - H3PO4,15).
To a 10 L 4 neck reactor equipped with a thermocouple, overhead stirrer,
condenser and nitrogen inlet was added lac (611 g, 1.15 mol) and water (3875 ml).
To the resulting suspension was added lysine (168 g, 1.15 mol). The reaction was
stirred for one hour at RT, heated to 50 °C then maintained at 50 °C with stirring for
an additional hour. The resulting hazy solution (pH = 4.55) was filtered through a 10
micron cuno filter into a 20 L 4 neck reactor equipped with a thermocouple, overhead
stirrer, condenser and nitrogen inlet. The reaction was heated to 50 °C then acetone
(8 L) was added rapidly. The reaction was allowed to warm to 50 °C then acetone (4
L) was added at a moderate rate keeping the reaction temperature above 45 °C. The
reaction was seeded with lab (0.200 g) then cooled to room temperature over 5 hours
resulting in a slurry. The slurry was stirred overnight at room temperature then
filtered. The wet cake was washed with acetone (4 L) then dried in a vacuum oven at
25 °C overnight with a bleed of moist air resulting in a fluffy white powder (751 g,
Example 13: Alternate preparation oflcb (Pro-drug of We)
OMe
To a 10 L reactor equipped with an overhead stirrer, thermocouple, distillation
apparatus, and nitrogen inlet was charged IVc (200.00 g, 422.39 mmol), CsaCOs
(344.06 g, 1.06 mol), KI (140.24g, 844.81 mmol) and NMP (1.00 L, 10.38 mol). The
reaction was stirred at room temperature resulting in a light brown heterogeneous
suspension. Di-tert-butyl chloromethyl phosphate (273.16 g, 1.06 mol) was added via
addition runnel and the reaction mixture was heated to 30 °C for 16-24 hours with
stirring after which time the reaction was cooled to 5 °C. To the reaction was added
DCM (1.5 L) then the reaction was slowly quenched with water (3.5 L) maintaining
the reaction temperature under 20 °C resulting in a biphasic mixture. The product
rich bottom layer was separated, washed with water (3.5 L x 3), then transferred back
to the reactor. The solution was concentrated under vacuum to a volume of 1 L
keeping the temperature below 25 °C. EPA was added (2 L) then the reaction was
concentrated under vacuum to a volume of 2 L keeping the temperature below 25 °C.
The reaction was then seeded with He (0.200 g), stirred overnight at room
temperature resulting in a slurry. The slurry was filtered and the wet cake was
washed with MTBE (1 L), dried in a vacuum oven at 50 °C overnight resulting in a
yellow/white powder (207.Ig, 70%). !H NMR (400 MHz, CDC13) 5 8.54 (s, 1H),
8.18 (s, 1H), 7.91 (s, 1H), 7.42 (s, 5H), 5.95 (d, J= 14.2 Hz, 2H), 4.06 (s, 3H), 3.97-
3.36 (m, 8H), 2.50 (s, 3H), 1.27 (s, 18H); 13C NMR (100 MHz, CDC13) 5 184.64,
170.65, 165.91, 161.60, 150.82, 145.38,141.89,134.96, 130.20,129.59,128.68,
127.58, 127.10, 124.77, 122.64, 115.22, 83.90, 83.83, 73.69, 73.63, 56.95, 46.04,
41.66, 29.61,29.56,13.90; ES+ MS m/z (rel. intensity) 696 (MH+,10), 640 (MH+ -
isobutylene, 30), 584 (MPT - 2 isobutylene, 100).
To a 10 L 4 neck reactor equipped with a thermocouple, overhead stirrer,
condenser and nitrogen inlet was added He (200.24 g, 287.82 mmol), acetone (800.00
ml, 10.88 mol) and water (800.00 ml, 44.41 mol). The reaction was heated to 40 °C
and stirred for 18-24 hours. The reaction was cooled to 20 °C then tromethamine
(33.62g, 277.54 mmol) was added. The reaction was heated to 40 °C then stirred for
an additional hour until all solids were dissolved. The reaction was cooled to 20 °C
then filtered through a 10 micron cuno filter into a 10 L 4 neck reactor equipped with
a thermocouple, overhead stirrer, and nitrogen inlet. Acetone (3 L) was added
rapidly, followed by seeding with Icb (0.500 g), then additional acetone (3 L) was
added. The reaction was stirred at room temperature overnight resulting in a slurry
then filtered. The wet cake was washed with acetone (800 ml) then dried in a
vacuum oven at 50 °C overnight resulting in a fluffy white powder (165.91 g, 82%).
Supplementary Information:
Isolation of the Free-Acid Intermediate Ic:
In a 250 mL 3 neck reactor equipped with a thermocouple, overhead stirrer,
condenser and nitrogen inlet was added He (10.0 g, 14.37 mmol), acetone (40.00 ml,
544.15 mmol) and water (40.00 ml, 2.22 mol). The reaction was heated to 40 °C and
stirred for 14-24 hours. The reaction was cooled to 20 °C then stirred for three hours,
resulting in a slurry. The slurry was filtered, then the wet cake washed with acetone
(40.00 ml) then dried in a vacuum oven at 50 °C overnight resulting in a fluffy white
powder (7.00 g, 83%). NMR (400 MHz, DMSO-d6) 5 8.84 (s, 1H), 8.47 (s, 1H),
8.06 (s, 1H), 7.45 (s, 5H), 5.81 (d, /= 12.3 Hz, 2H), 4.03 (s, 3H), 3.91-3.19 (m, 8H),
2.39 (s, 3H); 13C NMR (500 MHz, DMSO-d6) 8 185.20,169.32, 165.85,160.75,
150.51, 146.30, 143.24, 135.53,129.74,129.22, 128.46,127.34, 127.09, 123.67,
122.73, 113.94, 72.90 (d, 2JC.P= 5 Hz), 57.01, 45.2 (bs), 40.8 (bs), 13.66. ES+ MS mfz
(rel. intensity) 486 (MH+ - H3P04) 100).
Example 14: Alternate Preparation oflbb (Pro-drug oflVb)
To a 10 L reactor equipped with an overhead stirrer, thermocouple, and
nitrogen inlet was charged IVb (400.00 g, 894.73 mmol), Cs2CO3 (873.70 g, 2.68
mol), KI (297.70g, 1.79 mol) and NMP (1.00 L, 10.38 mol). The reaction mixture
was stirred at room temperature resulting in a light brown heterogeneous suspension.
Di-tert-butyl chloromethyl phosphate (460.50 g, 1.78 mol) was added via addition
funnel and the reaction was heated to 30 °C for 16-24 hours at which time the
reaction was cooled to 5 °C. To the reaction was added n-BuOAc (2.4 L) then the
reaction was slowly quenched with water (4 L) maintaining the reaction temperature
under 20 °C resulting in a biphasic mixture. The bottom aqueous layer was removed
from the reactor, then the product rich top layer was seeded with lie, (0.40 g) then
stirred 3 hours at room temperature resulting in a slurry. The slurry was filtered then
the wet cake was washed with MTBE (1.6 L) then dried in a vacuum oven at 50 °C
overnight resulting in a yellow/white powder (483.2g, 81%). >H NMR (400 MHz,
CDC13) 5 8.35 (s, 1H), 8.27 (s, 1H), 8.22 (s, 1H), 7.90 (s, 1H), 7.42, (s, 5H), 5.92, (d,
= 14.9 Hz, 2H), 4.02-3.40 (m, 8H)3 1.24 (s, 18H); 13C NMR (100 MHz, CDC13) 8
182.75,170.64, 152.07, 144.03,134.91,133.96,131.82, 130.21,128.68,128.27,
128.00,127.07, 125.81, 124.01,113.82, 84.00, 83.93, 73.97, 46.12, 41.90, 29.57,
29.53; ES+MS m/z (rel. intensity) 558(MH+, 100).
Ibb
Mol. Wt. =703.62
To a 300 ml 4 neck reactor equipped with a thermocouple, overhead stirrer,
condenser, and nitrogen inlet was added lib (18.0 g, 26.87 mmol), EPA (36.00 ml,
470.92 mol) and water (36.00 ml, 2.0 mol). The reaction was heated to 40 °C and
stirred for 18-24 hours. The reaction was cooled to 20 °C then lysine (3.73, 25.54
mmol) was added. The reaction was stirred for 1 hour until all solids were dissolved.
IP A (54 ml) was added over 30 minutes followed by seeding with Ibb (0.180 g) and
stirring for an additional 30 minutes. IP A was added (18ml) over 1 hour then the
reaction was heated to 50 °C resulting in a thin slurry. The reaction was seeded with
Ibb (0.180 g) then IP A (36ml) was added over 2 hours then stirred for 12 hours
resulting in a slurry. The reaction was heated to 70-80 °C for 2 to 3 hours then
cooled to 50 °C. IPA (59ml) was added over 1 hour then additional EPA (121 ml)
was added over 1 hour. The reaction was cooled to 20 °C over 2 hours then stirred
for an additional 2 hours then filtered. The wet cake was washed with IPA (180 ml)
then dried in a vacuum oven at 50 °C overnight resulting in a white powder (15.43 g,
82%).
Supplementary Information:
Procedure for the Isolation of the Free-Acid Intermediate Ibc:
In a 500 ml 3 neck flask equipped with a thermocouple, overhead stirrer,
condenser, and nitrogen inlet was added lib (50.00 g, 74.76 mmol), Acetone (100.00
ml, 1.36 mol) and water (100.00 ml, 5.55 mol). The reaction was heated to 40 °C and
stirred for 18-24 hours.
In a 250 ml 3 neck flask equipped with a pH probe, magnetic stirbar, and
nitrogen inlet was added 150ml of the above Ibc solution then the pH was adjusted to
pH = 6.2 with ION NaOH. The solution was transferred to a separatory funnel, then
washed with EtOAc (100 ml) then DCM (100 ml), then transferred back the 250 ml 3
neck flask. The pH was adjusted to pH = 1.3 with 2 N HC1 followed by stirring for
three hours, resulting in a slurry which was filtered. The wet cake was re-slurried in
MTBE (150 ml) then filtered, followed by re-slurrying in THF/Water (100:1, 130 ml)
for 45 minutes, then filtered and dried in a vacuum oven at 50 °C overnight resulting
in a white powder (10.0 g, 33%). NMR (400 MHz, DMSO-d6) 6 8.69 (s, 1H), 8.62 (s,
1H), 8.42 (s, 1H), 7.98 (s, 1H), 7.41 (s, 5H), 5.47 (d, J= 13.3 Hz, 2H), 3.99-3.18 (m,
8H); 13C NMR (100 MHz, DMSO-d6) 5 183.97, 169.23, 165.20, 151.69,145.91,
135.48, 133.83, 131.59,129.65, 129.11,129.03, 128.42, 127.77, 127.49,127.03,
122.62, 112.08, 72.57. ES+ MS m/z (rel. intensity) 558(MH+, 100).
130
Example 15: Preparation ofProdrug le
Preparation of 2-(l-(2-(4-methoxy-7-(3-methyl-lH-l,2,4-triazol-l-yl)-lHpyrrolo[
2,3-c]pyridin-3-yl)-2-oxoacetyl)piperidin-4-ylidene)-2-(pyridin-2-
yl)acetonitrile(TVe): 2-(4-methoxy-7-(3-methyl-1H-1,2,4-triazol-1 -yl)-1Hpyrrolo[
2,3-c]pyridin-3-yl)-2-oxoacetic acid (1.5g), 2-(piperidin-4-ylidene)-2-
(pyridin-2-yl)acetonitrile hydrochloride (1.5g), 3-(diethoxyphosphoryloxy)-l,2,3-
benzotriazin-4(3f/)-one (DEPBT) (2.1g) and Hunig's Base (2ml) were combined in
20 ml of DMF. The mixture was stirred at room temperature for 16 hours.
DMF was removed via evaporation at reduced pressure and the residue was
partitioned with MeOH (80ml). The precipitate was collected via filtration to provide
0.85g of the product, 2-(l-(2-(4-methoxy-7-(3-methyl-lH-l>2,4-triazol-l-yl)-lHpyrrolo[
2,3-c]pyridin-3-yl)-2-oxoacetyl)piperidin-4-ylidene)-2-(pyridin-2-
yl)acetonitrile (IVe). 1R NMR (500 MHz, DMSO-d6) 512.42 (s, 1H), 9.23 (m, 1H),
8.69 (m, 1H), 8.27 (m, 1H), 7.89 (m, 2H), 7.58 (m, 1H), 7.52 (m, 1H), 3.98 (s, 3H),
3.99 - 2.70 (m, 8H), 2.60 (m, 3H). MS m/z: (M+H)+ calcd for C^JfeNsOs 483.19,
found 483.18.
Phosphate ester (45. Ig, O.lrnol) and chloroiodomethane (200g, 1.14mol) were
combined in 100ml of benzene and the mixture was stirred at room temperature for
four hours before benzene was removed under vacuum. Then, 500ml of ethyl ether
was added to the residue and insoluble solid was filtered away. Concentration of the
filtrate provided di-tert-butyl chloromethyl phosphate, which was utilized in the next
step without any further purification.
Step three
NaH (0.2g, 95%) was added slowly into a suspension of 2-(l-(2-(4-methoxy-
7-(3-methyl-lH-l,2,4-triazol-l-yl)-lH-pyrrolo[2,3-c]pyridin-3-yl)-2-
oxoacetyl)piperidui-4-ylidene)-2-(pyridin-2-yl)acetonitrile (IVe) in dry THF (20ml)
and the mixture was allowed to stir for an hour at room temperature. Iodine (0.4g)
dissolved in dry THF (2ml) was added slowly into the stirring solution. The mixture
was stirred for additional 3 hours before 0.2g of NaH was charged. Following
completion of addition the resultant mixture was stirred at ambient temperature for an
additional 15 minutes and then di-tert-butyl chloromethyl phosphate, obtained from
step two, was added. After stirring for 16 hours, the reaction mixture was poured into
iced NH4OAc (30%) (50ml), followed by extraction with EtOAc (3 x 100ml). The
combined organic extracts were washed with water (50 ml) and then brine (50ml),
dried over NaaSOand concentrated under vacuum to afford a residue, which was
purified by silica gel chromatography (elution with EtOAc/EtsN (100/1)) to give
330mg of di-tert-butyl (3-(2-(4-(cyano(pyridin-2-yl)methylene)piperidin-1 -yl)-2-
oxoacetyl)-4-methoxy-7-(3-methyl-lH-l,2,4-triazol-l-yl)-lH-pyrrolo[2,3-c]pyridinl-
yl)methyl phosphate (He). !H NMR (500 MHz, CD3OD) 1H), 8.45 (m, 1H), 8.06 (m,lH), 7.92 (m, 1H), 7.60 (m, 1H), 7.43 (m, 1H), 6.05 (m,
2H), 4.11 (s, 3H), 4.00 (m, 1H), 3.82 (m, 1H), 3.76 (m, 1H), 3.60 (m, 1H), 3.04 (m,
1H), 2.95 (m, 1H), 2.85 (m, 1H), 2.80 (m, 1H), 2.52 (s, 3H), 1.30 (m, 18H). MS m/z:
(M+H)+ calcd for 705.29, found 605.30.
Di-tert-butyl (3-(2-(4-(cyano(pyridin-2-yl)methylene)piperidin-1 -yl)-2-
oxoacetyl)-4-methoxy-7-(3-methyl-1H-1,2,4-triazol-1 -yl)-1 H-pyrrolo[2,3-c]pyridinl-
yl)methyl phosphate (He) was dissolved in 8ml of a mixed solution of TFA and
dichloromethane (10% TFA/CH2C12) and the mixture was stirred for three hours.
All the solvents were removed under vacuum and the residue was purified using a
Shimadzu automated preparative HPLC System to give 25mg of tert-butyl (3-(2-(4-
(cyano(pyridin-2-yl)methylene)piperidin-l-yl)-2-oxoacetyl)-4-methoxy-7-(3-methyl-
1 H-1,2,4-triazol-1 -yl)-1 H-pyrrolo[2,3-c]pyridin-1 -yl)methyl hydrogen phosphate
(H'e) and 33mg of (3-(2-(4-(cyano(pyridin-2-yl)methylene)piperidin-l-yl)-2-
oxoacetyl)-4-methoxy-7-(3 -methyl-1 H-1,2,4-triazol-1 -yl)-1 H-pyrrolo [2,3-c]pyridinl-
yl)methyl dihydrogen phosphate (le).
tert-Butyl (3-(2-(4-(cyano(pyridin-2-yl)methylene)piperidin-1 -yl)-2-
oxoacetyl)-4-methoxy-7-(3 -methyl-1 H-1,2,4-triazol-1 -yl)-1 H-pyrrolo [2,3 -cjpyridinl-
yl)methyl hydrogen phosphate (H'e): !H NMR (500 MHz, CD3OD) 8.83 (m, 1H),
8.55 (m, 1H), 8.35 (m, 1H), 7.92 (m, 2H), 7.54 (m, 1H), 7.41 (m, 1H), 5.86 (m, 2H),
3.98 (s, 311), 3.96 (m, 1H), 3.72 (m, 1H), 3.65 (m, 1H), 3.47 (m, 1H), 2.92 (m, 1H),
2.85 (m, IH), 2.71 (m, IH), 2.65 (m, IH), 2.40 (s, 3H), 1.15 (m, 9H). MS m/z:
(M+H)+ calcd for C3oH34N8O7P 649.23, found 649.22.
(3-(2-(4-(Cyano(pyridin-2-yl)methylene)piperidin-l-yl)-2-oxoacetyl)-4-
methoxy-7-(3-methyl-lH-l,2,4-triazol-l-yl)-lH-p}Trolo[2,3-c]pyridin-l-yl)methyl
dihydrogen phosphate (le): JHNMR (500 MHz, DMSO-d6) (58.88 (m, IH), 8.65 (m,
IH), 8.50 (m, IH), 8.06 (m, IH), 7.90 (m, IH), 7.49 (m, 2H), 5.82 (m, 2H), 4.04 (s,
3H), 3.96 (m, IH), 3.88 (m, IH), 3.72 (m, IH), 3.46 (m, IH), 2.94 (m, IH), 2.82 (m,
2H), 2.73 (m, IH), 2.40 (m, 3H); 13C NMR (125 MHz, DMSO-d6) 160.6, 159.1, 151.0, 150.4, 149.5, 146.2, 143.1, 137.4, 129.1, 127.2, 124.4, 123.6,
122.6, 117.4, 116.3, 113.9, 110.0,72.8,56.9,48.4,44.4, 36.4,34.0, 13.6. MS m/z:
(M+H)+ calcd for C^HseNgOyP 593.17, found 593.14.
Example 16: Preparation ofProdruglf
To a mixture of IVf (99.5 mg, 0.21 mmol) in l-methyl-2-pyrrolidinone (1.0
ml) at r.t. in a capped vial was added KI (144 mg, 0.87 mmol) and CsaCOs (416 mg,
1.28 mmol)), and the mixture was stirred for about 5 min. Di-tertbutyl chloromethyl
phosphate reagent (218 mg, 0.84 mmol) was then added dropwise. The resulting
mixture was then stirred at 35 to 40°C for 20 hours. The mixture was then diluted
with H2O (about 8 ml) and extracted with EtOAc (about 8 ml). The organic extract
was separated and evaporated to give the di-t-butyl chloromethyl phosphate ;
Analytical HPLC method: Solvent A 10% MeOH-90% H2O-0.1%TFA; Solvent B
90% MeOH-10% H2O-0.1%TFA; Start %B = 0, Final %B = 100, Gradient time =
2min, Flow Rate = 5mL/min, Column: XterraMS C18 S7 3.0x50mm; LC/MS: (ES)
m/z (M+H)+ = 694.22, HPLC Rt = 1.243.
A mixture of Intermediate Ilf in H20/isopropanol (1.0 ml/1.0 ml) in a
stoppered round bottom flask was stirred at 40°C for 9.5 hours. The mixture was
then cooled to r.t., and the solution transferred to a vial by using a pipette. MeCN
(1.0 ml) was added to this solution, which was then added isopropanol slowly and
with intermittent stirring using a spatula. The off white precipitates were then
filtered, washed with isopropanol (2 x 1.0 ml) and then dried under high vacuum to
give the prodrug If; !H NMR (500 MHz): (DMSO-fe) 5 8.76 (s,lH), 8.71 (s, 1H),
8.69 (s, 1H), 8.49 (s, 1H), 8.09 (d, J- 8, 1H), 8.06 (s, 1H), 7.89 (d, J= 1,1H), 7.85
(app t, 1H), 7.59 (app t, 1H), 5.68 (d, J- 13,2H), 4.00 (b m, 2H), 3.90 (b m, 2H),
3.85 (b m, 2H), 3.65 (b m, 2H); Analytical HPLC method: Solvent A 10% MeOH-
90% H2O-0.1%TFA; Solvent B 90% MeOH-10% H2O-0.1%TFA; Start %B = 0,
Final %B = 100, Gradient time = 2min, Flow Rate = SmlVmin, Column: Xterra MS
CIS S7 3.0x50mm; LC/MS: (ES) m/z (M+H)+ = 582.00, HPLC Rt = 1.797.
To be successful, the conversion of the prodrug into parent must be initiated
by alkaline phosphatases in man. Qualitative in vitro studies using human placental
alkaline phosphatase and in vivo studies in rats showed that conversion of prodrug
was rapid both in vitro with human enzymes and in in vivo in rats. Ideally, the rate of
conversion will be rapid so that only limited exposure to prodrug occurs and
maximum exposure to active parent antiviral agent will result. Data from studies
(below) shows that in all three prodrug examples evaluated in rats, the prodrug is
rapidly converted to active parent drug and that plasma levels of prodrug are very low
in comparison to parent drug at all data points. These studies were done at doses in
which doses of parent drug and the dose equivalent from phosphate prodrug were low
and approximately equal, ~5mg/kg. Since the advantages of prodrugs are to
overcome dissolution limited absorption, at low doses the advantages of the prodrugs
over less soluble parent molecules for clinical use in patients will not be obvious.
The low dose in vivo studies were used to determine if the prodrugs were generating
parent molecule. The solubility of the parent molecules IV, is dependent on
crystalline form. A crystalline form is preferred for drug development. The data for
all of the parent molecules can be summarized by saying that the aqueous solubility
of crystalline material for all the parent molecules IV is much less. Thus, the intrinsic aqueous solubility of the parent molecules is low and
plays a major role in causing dissolution-limited absorption at higher doses.
Table 1 - Biological and Pharmaceutical Properties
ofN-methyl dihydrogen phosphate (or salts) Azaindoleoxoacetic Piperazine
Derivatives
Solubility
(mg/mL), pH 6.5
In vitro conversion
in Alkaline
phosphatase
(note 1)
In vivo conversion
in Rats-oral
(note 2) MAP study
In vivo conversion
in Rats-iv
(note 2) MAP study
Compoundla
(disodium salt)
Complete and rapid
conversion to parent
without any
intermediate
formation
Rapid generation of
parent in plasma
Rapid generation of
parent in plasma
Compound Ib
(disodium salt)
Complete and rapid
conversion to parent
without any
intermediate formation
Rapid generation of
parent in plasma
Rapid generation of
parent in plasma
Compound Ic
(acid form)
Complete and rapid
conversion to parent
without any intermediate
formation
Rapid generation of
parent in plasma
Rapid generation of
parent in plasma
Note 1: The prodrug derivative (cone. ~0.2 mM) was incubated with alkaline
phosphatase (human placenta, Sigma, ~1.4 unit) in pH 8 Tris buffer (cone. ~0.03M,
ImL), and disappearance of the prodrug and formation of the parent were monitored
by HPLC and LC/MS. hi most cases, the prodrug completely disappeared,
corresponding with formation of the parent within an hour or two, and no other
intermediate was detected.
Note 2: The prodrug was administered in rats by the oral (at the dose equiv. to 5
mg/Kg of the parent) or intravenous route (at the dose equiv. to 1 mg/Kg of the
parent). The plasma levels indicate rapid conversion to the parent with no detectable
amount of the prodrug (po).
In the tables below the term "LLQ" means lower Limit of quantitation (i.e., not
detected).
Total AUC of parent after PO administration of Prodrug
Total AUC of parent after PO administration of parent (historic data)
A dose escalation study D of one of the prodrugs (lea) was carried out in rats
in order to demonstrate the significant advantages of prodrugs over the parent for
potential use in the treatment of HIV-1 patients after oral dosing. The exposure data
and measured parameters from the prodrug dose escalation study were compared to
similar data from historical studies conducted with parent molecules.
Figures 3 and 4 compare the AUC (the area under the curve, a measure of
exposure to drug in the rat) of IVc from oral dosing of prodrug lea (study D) to that
obtained from dosing parent molecule IVc (Study E) and a rat toxicokinetic study
(TK). Details for the historical IVc dose escalation (Study E) and the rat TK study
(F) are shown in these figures.
As can be seen from Figures 3 and 4, the AUC and Cmax of parent molecule
after oral administration of the prodrug (triangles) is greater than that which resulted
from administration of the parent drug in two separate studies. Clearly, the data
shows that in order to maximize exposure multiples of drug in plasma, the prodrug
offers a surprising advantage. Since the chemical structures of this class of molecules
are similar, prodrugs of the class are expected to show enhancement in exposure from
administration of prodrugs rather than parent. Given the uncertainty of improving
oral exposure with phosphate prodrugs and the novelty of the new compounds, this
result was not obvious and is surprising in its magnitude.
W and Oral Rat PK Study Protocol of Phosphate Prodrugs Studies A,B,and C
Compounds Ic (phosphate prodrug of F/c), Ib (phosphate prodrug of IVb),
and la (phosphate prodrug of IVa) were administered separately to groups of three
male Sprague-Dawley rats by IV bolus (1 mg/kg; all doses listed in this document
were parent compound equivalent) or oral gavage (5 mg/kg). The rats for oral dosing
studies were fasted overnight. Compound Ic was administered as a free acid, whereas
the other two were as sodium salts. The dosing solutions of all three prodrugs for
both IV and oral administration were prepared in 100% normal saline at 1 mg/mL
(dosing solution concentrations were parent compound equivalent). Plasma samples
were collected in EDTA vacutainers over 24 lirs, and analyzed by LC/MS/MS for
both the prodrugs and parent molecules. Pharmacokinetic analysis was performed on
Kinetica™.
Procedures for LC/MS/MS analysis are shown in the protocols below.
The results of this study are shown in Tables 2-4, middle two columns.
Oral Dose Escalation Study Protocol of lea in Rats (Study D)
Groups of three fasted male Sprague-Dawley rats were orally administered
compound lea (disodium salt) at 4.5, 21, and 163 mg/kg (doses were FVc equivalent).
The dosing solutions were prepared in water at 1, 5, and 20 mg (compound Ic (free
acid) equivalent)/mL for the doses of 4.5, 21, and 163 mg (compound FVc
equivalent)/kg, respectively. Plasma samples were collected in EDTA vacutainers
over 24 hrs, and analyzed by LC/MS/MS for both Ic and IVc. Pharmacokinetic
analysis was performed on Kinetica™.
The results of this study are shown in Table 46 and Figures 3-5.
2. The AUC conversion ratio at 5 mg/kg of IVc from lea, calculated as the ratio of
We AUC after lea dosing divided by IVc AUC after direct dosing of IVc, was
0.99.
3. The prodrug lea was only detected at ~20-40 nM in one to two samples in each rat
in the 200 mg/kg dose group.
In Vivo Methods
Procedure for Study Al: PO and IV Administration ofWa to Rats; PO Dose was
5mg/kg
Compound FVa was administered in a polyethylene glycol 400
(PEG400)/ethanol (EtOH) solution (90/10, v/v) unless noted otherwise. Plasma and
tissue samples were collected and stored at -20°C until analysis.Male Sprague-
Dawley rats (300 - 350 g, Hilltop Lab Animals, Inc., Scottdale, PA 15683) with
cannulas implanted in the jugular vein and/or bile duct were used in the
pharmacokinetic studies of compound IVa. Rats were fasted overnight in PO studies.
Blood samples (0.3 mL) were collected from the jugular vein in EDTA-containing
microtainer tubes (Becton Dickinson, Franklin Lakes, NJ 07147) to obtain plasma. In
the IV studies, a dose of 1 mg/kg was administered to 3 rats over 0.5 min, and serial
plasma samples were collected before dosing and 2, 10, 15, 30, 45, 60, 120, 240, 360,
480, and 1440 min after dosing. In the PO studies, rats (n = 3) received PO doses of
5 and 100 mg/kg. Serial plasma samples were taken before dosing and 15, 30, 45, 60,
120,240, 360, 480, and 1440 min after dosing.
The oral (PO) results of this study are shown in the last right most column of
For the IV and PO pharmacokinetic studies of COMPOUND JVb in rats,
COMPOUND IVb was dissolved in PEG-400/ethanol (90/10) as a solution. For the
IV and PO pharmacokinetic studies of COMPOUND IVB in dogs, COMPOUND FVb
was dissolved in PEG-400/ethanol (90/10) with pH adjustment with 0.1 N NaOH.
Details of the formulations are provided in Table 6.
Rat. Male Sprague-Dawley rats (300-350 g, Hilltop Lab Animals, Inc., Scottdale,
PA) with carmulas implanted in the jugular vein and/or bile duct were used. The rats
were fasted overnight in the PO pharmacolcinetic studies. Blood samples of 0.3 ml
were collected from the jugular vein in EDTA-containing microtainer tubes (Becton
Dickinson, Franklin Lakes, NJ), and centrifuged to separate plasma.
hi the IV study, COMPOUND IVb was delivered at 1 mg/kg as a bolus over
0.5 min (n = 3). Serial blood samples were collected before dosing and 2, 10, 15, 30,
45, 60,120,240, 360, 480, and 1440 min after dosing.
In the PO study of COMPOUND IVb, the rats (n = 3) received an oral dose of
5 mg/kg of COMPOUND IVB. Serial blood samples were collected before dosing
and 15, 30, 45, 60, 120, 240, 360, 480, and 1440 min after dosing.
The results of this oral (PO) study are shown in Table 3, right most column.
Bioanalytical Methods for In Vivo Studies Analyzing for Wb
This refers to method for analyzing for concentration levels of IVb in rat
plasma samples (used for studies B and Bl).
Quantitation of COMPOUND IVb by LC/MS/MS in Plasma. Aliquots of plasma
samples from rat, dog, monkey or chimpanzee studies were prepared for analysis by
precipitating plasma proteins with two volumes of acetonitrile containing the internal
standard,.COMPOUND IVa. The resulting supernates were separated from the
precipitated proteins by centrifugation for 10 minutes and transferred to autosampler
vials. Samples were either prepared manually, or with the use of the Tomtec
automated liquid handler. An aliquot of 5 \\L was injected for analysis.
The HPLC system consisted of two Shimadzu LC10AD pumps (Columbia,
MD), a Shimadzu SIL-HTC autosampler (Columbia, MD), and a Hewlett Packard
Series 1100 column compartment (Palo Alto, CA). The column was a YMC Pro Cl 8
(2.0 x 50 mm, 3 fom particles, Waters Co., Milford, MA), maintained at 60°C and a
flow rate of 0.3 ml/min. The mobile phase consisted of 10 mM ammonium formate
and 0.1% formic acid in water (A) and 100% 10 mM ammonium formate and 0.1%
formic acid in methanol (B). The initial mobile phase composition was 95% A.
After sample injection, the mobile phase was changed to 15% A/85% B over 2
minutes and held at that composition for an additional 1 minute. The mobile phase
was then returned to initial conditions and the column re-equilibrated for 1 minute.
Total analysis time was 4 minutes.
The HPLC was interfaced to a Micromass Quattro LC. Ultra high purity
nitrogen was used as the nebulizing and desolvation gas at flow rates of 100 L/hr for
nebulization and 1100 L/hr for desolvation. The desolvation temperature was 300°C
and the source temperature was 150°C. Data acquisition utilized selected reaction
monitoring (SRM). Ions representing the (M+H)+ species for IVb and the internal
standard were selected in MSI and collisionally dissociated with argon at a pressure
of 2 x 10" torr to form specific product ions which were subsequently monitored by
MS2. The transitions, voltages and retention times are summarized in Table 7.
The plasma standard curve ranged from 4 to 8000 ng/ml, the brain curve from
1-1000 ng/ml. The curves were fitted with a quadratic regression weighted by
reciprocal concentration (1/x). Standards were analyzed in duplicate. Quality control
(QC) samples, prepared in blank plasma, at three concentrations within the range of
the calibration curve were also analyzed in triplicate with each plasma analytical set.
For this compound, the predicted concentrations of 90% of the plasma QCs were
within 20% of nominal concentration, indicating acceptable assay performance.
Vehicles and Formulations. Referring to Table 8, when the vehicle used contains
NaOH, Compound IVc solution formulations were pH adjusted using NaOH to obtain
a pH of 8.6-9.0, where the compound is partially ionized, based on it's pKa at 8.4.
D). Aliquots of plasma samples from rat, dog, monkey and chimpanzee studies were
prepared for analysis by precipitating plasma proteins with two volumes of
acetonitrile containing the internal standard, compound IVa. The resulting supernates
were separated from the precipitated proteins by centrifugation for 10 minutes and
transferred to autosampler vials. Samples were either prepared manually, or with the
use of the Tomtec automated liquid handler. The HPLC system consisted of two
Shimadzu LC10AD pumps (Columbia, MD), a Shimadzu SIL-HTC autosampler
Columbia, MD), and a Hewlett Packard Series 1100 column compartment (Palo Alto,
CA). The column was a YMC Pro CIS (2.0 x 50 mm, 3 jam particles, Waters Co.,
Milford, MA), maintained at 60°C and a flow rate of 0.3 ml/min. The mobile phase
consisted of 10 mM ammonium formate and 0.1% formic acid in water (A) and 100%
10 mM ammonium formate and 0.1% formic acid in methanol (B). The initial
mobile phase composition was 95% A. After sample injection, the mobile phase was
changed to 15% A/85% B over 2 minutes and held at that composition for an
additional 1 minute. The mobile phase was then returned to initial conditions and the
column re-equilibrated for 1 minute. Total analysis time was 4 minutes.
The HPLC was interfaced to a Micromass Quattro LC. Ultra high purity
nitrogen was used as the nebulizing and desolvation gas at flow rates of 100 L/h for
nebulization and 1100 L/h for desolvation. The desolvation temperature was 300°C
and the source temperature was 150°C. Data acquisition utilized selected reaction
monitoring (SRM). Ions representing the (M+H)+ species for IVc and the internal
standard were selected in MS 1 and collisionally dissociated with argon at a pressure
of 2 x 10' torr to form specific product ions which were subsequently monitored by
MS2. The transitions, voltages and retention times are summarized in Table 9.
The plasma standard curve ranged from 4 to 8000 ng/ml, the brain curve from
1-1000 ng/ml. The curves were fitted with a quadratic regression weighted by
reciprocal concentration (1/x). Standards were analyzed in duplicate. Quality control
(QC) samples, prepared in blank plasma, at three concentrations within the range of
the calibration curve were also analyzed in triplicate with each plasma analytical set.
For this compound, the predicted concentrations of 90% of the plasma QCs were
within 20% of nominal concentration, indicating acceptable assay performance.
Quantitation of Three Pro-Drugs and their Parent Compounds by LC/MS/MS in
Biological Matrices
This LC/MS/MS assay was developed to investigate three pro-drug
compounds and their respective parent molecules in biological matrices. The three
pro-drug compounds were: Compounds la, Ic, and Ib and their other respectives
salts or free acids. Note this assay is used for the free acid and salt forms of the three
prodrugs as molecular ion detected is independent of salt counterion. Thenrespective
parent compounds were: IVa, IVc, and IVb.
The HPLC system consisted of Shimadzu LClOADvp pumps (Columbia,
MD) and HTC PAL autosampler (Leap Technologies, Gary, NC) linked to a Synergi
Hydro-RP analytical column (2.0 x 50 mm, Phenomenex, Torrance, CA). Mobile
phase A consisted of 0.1% Formic Acid in water; mobile phase B was 0.1% formic
acid in acetonitrile. LC flow rate was 0.4 mL/min into the mass spectrometer. The
initial mobile phase composition was 10% B ramped to 75% B over 1.75 min, held at
that composition for 0.25 min, ramped to 100% B over 0.1 min, held for 0.6 min,
returned to initial conditions over the next 0.1 minute and then re-equilibrated. Total
analysis time was 4 min. Retention times for all analytes ranged between 1.5 and 2.6
min.
The HPLC system was interfaced to a Sciex API3000 triple quadrupole mass
spectrometer (Toronto, Canada) equipped with the Turboionspray source set at 450°C
and ionspray voltage set to 4.5 kV. UHP nitrogen was used as nebulizer and auxiliary
gases with pressures of 80 psi and 7L/min, respectively. The analysis was performed
in positive ion mode. The transitions monitored for all compounds and their collision
energies (CE) were: m/z 533.41 > 435.24 for la (CE=19); m/z 584.46 > 486.29 for Ic
(CE=23); m/z 558.31 > 432.13 for Ib (CE=19); 423.39 > 204.96 for IVa (CE=31);
474.36 > 255.97 for IVc (CE=29); 448.35 > 105.20 for IVb (CE=35).
To accommodate a wide variety of biological sample matrices, acetonitrile
precipitation was used in sample preparation. Test samples and standards were
transferred to a 96 well plate using the Packard Multiprobe II (Packard Instruments,
Downers Grove, IL). 200 |J,L of acetonitrile containing the internal standard (BMS-
647257, 500 nM) was added to 100 pL aliquots of both test samples and standards in
the 96 well plate using the Tomtec Quadra 96. The plate was then vortexed for
approximately 3 minutes and centrifuged at 3000 rpm for 15 minutes. Using the
Tomtec Quadra 96, 150 [XL of supernatant was transferred from the plate to a clean 96
deep well plate. 150 uL of 0.2% formic acid in water was then added to each well
using the Tomtec Quadra 96 and the plate was vortexed before analysis.
Standard curves at eight concentration points from 5 nM to 10 jiM were
prepared from stock solutions in acetonitrile and serially diluted in matrix for both
pro-drug and parent compounds. Standard curves were transferred in duplicate 100
uL aliquots to a 96 well plate containing the test samples, extracted with the test
samples as described above, and injected at the beginning, middle, and end of the
analytical sequence. The standard curves were fitted with a linear regression
weighted 1/x . Data and chromatographic peaks were processed and concentrations
of standards and unknowns were quantitated using PEBiosystems Analyst™ 1.1.
In Vivo Methods
Conditions for Study Cl, E andF (Rat PK, MAP and TK Studies)
For the IV and PO pharmacokinetic studies of compound We in rats,
compound IVc was dissolved in PEG-400/ethanol (90/10) as a solution. Please refer
to Table 8.
Rat. Male Sprague-Dawley rats (300-350 g, Hilltop Lab Animals, Inc., Scottdale,
PA) with cannulas implanted in the jugular vein and/or bile duct were used. The rats
were fasted overnight in the PO pharmacokinetic studies. Blood samples of 0.3 ml
were collected from the jugular vein in EDTA-containing microtainer tubes (Becton
Dickinson, Franklin Lakes, NJ), and centrifuged to separate plasma.
In an IV study, compound IVc was delivered at 1 mg/kg as a bolus over 0.5
min (n = 3). Serial blood samples were collected before dosing and 2, 10, 15, 30, 45,
60,120,240, 360, 480, and 1440 min after dosing.
PO Single Dose Study Cl
In the PO study Cl of Compound IVc, the rats (n = 3) received an oral dose of
5 mg/kg of Compound IVc. Serial blood samples were collected before dosing and
15, 30, 45, 60,120, 240, 360, 480, and 1440 min after dosing. The oral (PO) results
from Study Cl are in Table 4, right most column.
Oral (PO) Dose Escalation Study E
In the oral dose escalation study E of Compound IVc, groups of rats (n = 2 per
group) received oral doses of 25, 75, and 200 mg/kg. At 25 mg/kg, the dosing
solution was in solution; at the higher doses, the dosing solutions were suspensions.
Serial blood samples were collected before dosing and 15, 30, 45, 60,120, 240, 360,
480, and 1440 min after dosing. Brain samples were collected at 1440 min to assess
brain penetration. The brain samples were blotted dry and the wet weights were
recorded. The oral (PO) results from Study E are in Table 46.
2-Week Oral Dose Rat Toxicology Study F
In the 2-week oral rat study F (n=six/sex/group), Compound IVc was
administered at daily doses of 15, 75, or 200 mg/kg. Toxicokinetic evaluations on
days 1 and 14 indicated that systemic exposures (AUCo-24h) of Compound IVc were
generally dose related but were not dose proportional (see Table 5), with no evidence
of autoinduction or accumulation. On Day 14, AUC0-24h values were slightly higher
in females (644 |lghr/ml) compared to males (526.88 lir/ml) at dosages 200
mg/kg/day. The oral (PO) results from Study F are in Table 5.
Map Study G: PO and IV Dosing Study of Diester Ila in Rats
Structure of Compound Ila
The procedure for the oral dosing leg of MAP study Al was followed except
that diester Ila was utilized in place of Compound IVa. Analysis for compound IVa
showed that dosing of the diester Ila by oral route produced substantial IVa. The data
is described in Table 10 below:
(Table Removed)
A significant number of studies were done to demonstrate and characterize the
surprising utility of the prodrugs I. Dose escalation exposure experiments comparing
exposure of parent molecules after dosing prodrug and parent were carried out in rats
and dogs for prodrugs I of parent molecules IVa, IVb, and IVc. The effect of food
and dose on exposure of IVa after dosing prodrug lab or parent IVa was compared in
dogs. The prodrug showed suprising ability to improve exposure and avoid effects of
feed as compared to parent. Low dosage full pharmacokinetic studies (oral and IV
dosing) were carried out in rats dogs and monekys for prodrugs lab, Ibb, and Icb to
show conversion to parent compounds IVa, IVb,, and IVc respectively. Oral dosing
studies hi rats were carried out for sprodrug le (free acid), and for parent compound
IVf to demonstrate conversion and systemic exposure of parents We and IVf
respectively. Data is shown above or below in this application.
Additional profiling Section 1
Additional Studies -with lab:
lac is the free acid phosphate prodrug of the N-hydroxymemyl adduct of IVa
and is hydrolyzed by alkaline phosphatase (ALP) to form IVa. lab, a mono-lysine salt
of lac, was used for all of the following studies.
TV and PO pharmacokinetic studies of lab were conducted in rats, dogs and
monkeys, hi all cases, blood samples were collected in the presence of EDTA. The
presence of EDTA, a known ALP inhibitor, minimized significant ex vivo conversion
of lab during sample processing. IVa was rapidly formed following IV
administration of lab. Good oral bioavailabilities (62-94%) of TVa were observed
after administration of lab in rats, dogs and monkeys with very little or no lab present
in plasma. Since there are high levels of ALP expression in the gut, it is likely that
following oral administration of lab, lab is hydrolyzed by ALP present at the brush
border membranes of the intestinal lumen to form IVa, which is rapidly absorbed due
to its high permeability.
In vitro incubation studies were conducted for a qualitative assessment of
ALP-dependent hydrolysis of lab in different tissues. lab was hydrolyzed in the
presence of serum and hepatocytes from rat, dog, monkey and human, as well as
human placental ALP. On the occasions where lab and IVa were measured, the
conversion of lab to IVa was near stoichiometric. Due to hydrolysis in serum, the
protein binding of lab could not be determined. Based on the in vitro data, it is
anticipated that lab will be hydrolyzed by human ALP and that IVa will be formed
after oral administration of lab to human subjects.
The crystalline solubility of lab at room temperature increases from 0.22
mg/ml at pH 1.4 to >12 mg/ml at pH 5.4 and pH 8.9; aqueous solutions containing
>100 mg/mL have been prepared for in vivo toxicology studies. In comparison, the
aqueous solubility of the parent compound, IVa, at room temperature as crystalline
material was determined to be 0.04 - 0.9 mg/mL (pH range of 1.5 - 10). lab exhibits
acceptable solution and solid stabilities.
The higher aqueous solubility of lab provides a means to overcome the
dissolution-rate limited absorption of IVa below certain doses and thereby increased
the exposures of IVa in oral dose escalation and toxicokinetic studies. lab, when
dosed orally at ~200 mg/kg of IVa equivalent, provided 2-fold higher AUC of IVa in
rats and dogs, without significant plasma exposure to the prodrug, as compared to the
AUC from the historical IVa suspension studies at the similar dose. Moreover, the
AUC and Cmax values of IVa in fasted dogs receiving lab dry-filled capsules (200
mg/dog of IVa equivalent) were 38 and 58 times, respectively, those attained in fasted
dogs given the IVa clinical capsule formulation, and 4 and 6 times, respectively, those
attained in fed dogs given the IVa clinical capsule formulation.
No significant differences in AUC and Cmax of IVa were observed between
fasted and fed dogs receiving lab, whereas a 9-fold improvement was observed in fed
dogs as compared to fasted dogs receiving IVa. These data suggest that efficacious
blood levels of IVa may be achieved in HIV-infected patients without the requirement
for a high fat meal. The spray dried form of IVa gave rise to similar exposure levels
of IVa as that observed from lab in dogs.
Single-Dose Toxicokinetic Tolerability Study in CD Rats
A 1-day oral toxicokinetic study in rats was conducted using the prodrug lab
(monolysine salt). lab was administered at dosages of 16, 72, and 267 mg/kg (free
acid) by oral gavage to three male rats/group using water as the vehicle (solution
formulation). The dosages of prodrug free acid correspond to IVa (parent) molar
equivalent dosages of 13, 57, and 211 mg/kg, respectively. The endpoint evaluated
was plasma toxicokinetics of lab and IVa in the individual rats.
The mean toxicokinetic values are provided in Table 12.
(Table Removed)
Mean maximum plasma concentration (Cmax) of both lab (prodrug) and IVa
(parent) was achieved within 1.1 hour post-dose. The plasma area under the plasma
concentration-time curve (AUC) of the prodrug was rats given dosage, and Cmax increased in a less than dosage-proportional manner between 72
and 267 mg/kg of lab.
A comparison of IVa AUC obtained in rats given either IVa (2) or lab, is
shown in Figure 6.
Solubility in preclinical formulations has been an issue. The AUC of IVa is
equivalent for both parent and prodrug at lower dosages (e.g., both were formulated as solutions (PEG-400 for parent and water for prodrug) but at
a high dosage (e.g., 200 mg/kg) the neutral parent was formulated as a suspension
whereas the prodrug salt was formulated as an aqueous solution.
A 2-week rat toxicity study using dosages of 5, 50, or 500 mg/kg BID to
support the IND is ongoing (3). The in-life phase of the study has been completed,
and there were no noteworthy in-life observations.
Single-Dose Toxicokinetic and Tolerability Study in Dogs
A multi-phase study was conducted to evaluate the tolerability of the prodrug,
lab (monolysine salt) at dosages of 24, 90, or 240 mg/kg (free acid, molar equivalent
to 19, 71, or 190 mg/kg of parent IVa, respectively) and the toxicokinetics of lab and
IVa (4). lab was administered to two female dogs/group once daily either as an
aqueous solution (24 or 90 mg/kg) or dry-filled capsules (24, 90 [once and twice
daily] or 240 mg/kg). The endpoints were: clinical signs, body weight, food
consumption, and plasma toxicokinetics of lab and IVa. In all cases, a 1-week
washout period was used between doses for all phases of the study.
The plasma toxicokinetic values from the initial phase of the study are shown
in Table 13.
(Table Removed)
lab was not detected in the plasma samples. Mean maximum plasma
concentration (Cmax) of IVa was achieved between 1-2 hours post-dose. When lab
was given as a solution, both the Cmax and AUC increased in less than dosage
proportional manner between 24 and 90 mg/kg. Emesis was observed at about 30
minutes after dosing in both dogs given 90 mg/kg. The Cmax and AUC of IVa were
equivalent following lab administration at 24 mg/kg using either dry-filled capsules
or an aqueous solution.
Other than emesis, there were no clinical signs observed, and there no effects
on body weight and food consumption.
To determine whether emesis could be eliminated/reduced by administration
of lab as a dry-filled capsules, the next phase of the study was conducted using
dosages of 90 or 240 mg/kg, and 90 mg/kg given twice 4 h apart (BE)). The
toxicokinetic values are shown in Table 14.
(Table Removed)
There was no difference in Cmax or AUC between dogs given 90 or 240
mg/kg of lab administered by dry-filled capsules. Emesis was observed in Dogs
#1201, #2201, and #2202 about 1 hour after dosing. The vomit was collected and
assayed for lab content to estimate the amount of the total dose that was lost; the
percentage of estimated total dose lost was #2202. Although the estimations of "dose lost" do not appear to be quantitatively
consistent with the plasma AUC data, it does indicate that test article can be found in
vomit within a short time after dosing. lab was detected in plasma of the dogs, 0.005-
0.049 |iM at 1 hour post dose and 0.005-0.006 pM at 2 hours post dose; the prodrug
was not detectable at later time points.
A comparison of Wa AUC obtained in dogs given either IVa (5, 6) or lab, is
shown in Figure 7.
Vehicles and Formulations
Summary of Formulations Used for Key PK and Safety Studies
All in vivo PK studies in rats, dogs, and monkeys were performed using
aqueous solutions for PO and IV dosing. Toxicology and exposure studies in dogs
were performed with, aqueous solutions at dosages of 24 and 90 mg/kg and drug in
capsule formulations at dosages of 24, 90, and 240 mg/kg of lab, mono-lysine salt.
In the rat oral dose escalation study, lab was dosed as aqueous solutions at
concentrations of 4.5, 20.0, and 73.5 mg/mL (mono-lysine salt form of prodrug). A
significant improvement in AUC and Cmax of IVa, parent, after oral dosing of lab,
prodrug, were observed compared to the historical data of IVa oral dosing.
Drug in capsule formulations of lab at doses of 20 mg/kg of IVa equivalent
were used for food effect studies in dogs. The prodrug was compared to the clinical
capsule formulation of the parent compound, IVa, at 20 nig/kg. When IVa clinical
capsule was dosed, a 9-fold increase in exposure was seen in dogs fed a high fat meal
compared to fasted dogs. Upon dosing of the prodrug, lab, the exposure of IVa was
significantly higher and as expected, the exposure was not significantly different
between fasted and fed dogs.
Metabolism and Pharmacokinetics Summary
Summary of Findings and Interpretation
lab is the phosphate prodrug of the N-hydroxymethyl adduct of IVa and is
hydrolyzed by alkaline phosphatase (ALP) to form IVa. After administration of lab
to animals, therefore, plasma samples were prepared from blood collected in the
presence of EDTA, a known ALP inhibitor. Conversion of lab to IVa was minimal
( dog blood containing EDTA. No significant ex vivo conversion of lab is expected
during sample storage (-20°C) and analysis of lab.
The hydrolysis of lab was studied in animal and human in vitro systems.
Since multiple ALP isoforms are widely distributed in various tissues, quantitative in
vitro to in vivo correlations were not attempted (Fishman et al., 1968; Komoda et al.,
1981; Moss, 1983; Yora and Sakagishi, 1986; Sumikawa et al, 1990). Therefore, the
studies were limited to a qualitative assessment of ALP-dependent hydrolysis in
different tissues. lab was hydrolyzed in the presence of serum and hepatocytes from
rat, dog, monkey and human, as well as in human placental ALP. On the occasions
where lab and IVa were measured, the conversion of lab to IVa was near
stoichiometric. Due to hydrolysis in serum, the protein binding of lab could not be
determined.
None or very low levels of lab were detected in rat, dog and monkey plasma
after oral administration of lab. IVa was rapidly formed following IV administration
of lab in rats, dogs and monkeys. The W AUC conversion ratios were 1.5 in rats,
0.80 in dogs and 0.70 in monkeys, suggesting good conversion from lab to IVa.
Good oral bioavailabilities (62-94%) of IVa were observed after
administration of lab in rats, dogs and monkeys. More significantly, the higher
aqueous solubility of lab lessened the dissolution-rate limited absorption of IVa
below certain doses and thereby increased the exposures of TVa in oral dose
escalation and toxicokinetic studies (Tables 12-14 and Fig. 6-7). The AUC levels of
IVa in fasted dogs receiving lab capsules were about 40 times the levels in fasted
dogs given IVa clinical form capsules. Although a 40-fold difference is likely an
over-prediction of the clinical situation, based on the development experience with
IVa, lab clearly demonstrated the potential to improve the dissolution-rate limited
absorption seen with parent IVa.
To investigate the effect of food on the oral absorption of IVa hi dogs, lab and
IVa were administered in capsules under fasting and fed conditions. No significant
differences in AUC and Cmax were observed with lab, whereas a 9-fold
improvement was observed with IVa upon feeding. These data suggest potential
clinical benefits for HIV-infected patients, in whom efficacious blood levels of IVa
may be achieved without the requirement for a high fat meal.
Methods
The studies described in this report used the mono-lysine salt of lab, unless
stated otherwise.
Quantitation of lab andWa by LC/MS/MS
An LC/MS/MS method was developed for the analysis of lab and IVa in
plasma samples from the animal phannacolcinetic studies as well as in acetonitrile
supernatant from in vitro incubation studies. For the analysis in plasma, a Packard
Multiprobe instrument was used to transfer 50 p.L of each standard, QC, and plasma
sample to a clean 96-well plate for protein precipitation extraction. After the addition
of 200 |iL of acetonitrile containing the internal standard We, the samples were
vortex mixed and the resulting supernatant was separated from the precipitated
proteins by centrifugation for 10 min. For the analysis in the supernatant generated
from the in vitro studies, an equal volume of the supernatant and acetonitrile
containing the internal standard was mixed. An aliquot of the above supernatant was
transferred using a Tomtec automated liquid handler to a second clean 96-well plate.
An equal volume of water was added, and the plate was capped and vortex mixed.
The HPLC system consisted of Shimadzu LClOADvp pumps (Columbia,
MD) and a HTC PAL autosampler (Leap Technologies, Gary, NC) linked to a
Phenomenex Synergi Fusion-RP analytical column (2.0 x 50 mm, 5 |i; Torrance,
CA). Mobile phase A consisted of 5 mM ammonium formate in water; mobile phase
B was 100% acetonitrile. LC flow rate was 0.38 rnL/min. The initial mobile phase
composition was 3% B, ramped to 60% B over 1.75 min and held for 0.25 min,
ramped to 100% B over 0.1 min and held for 0.8 min, returned to initial conditions
over the next 0.1 min, and re-equilibrated. Total analysis time was 4.0 min. The
retention time for lab, IVa and We was 1.50,1.67 and 1.73 min, respectively.
The HPLC system was interfaced to a Sciex API4000 triple quadrupole mass
spectrometer (Toronto, Canada) equipped with the Turboionspray source set at 550°C
and the ionspray voltage set to 4.5 kV. UHP nitrogen was used as nebulizer and
auxiliary gas with the pressure of 80 psi and 7 L/min, respectively. The collision
energies for lab, IVa and We were 21, 29 and 31 volts, respectively. Data acquisition
utilized selected reaction monitoring (SPJVI). Ions representing the positive ion mode
(M+H)+ species for lab, Wa and the internal standard were selected in MSI and
collisionally dissociated with nitrogen and optimized collision energies to form
specific product ions subsequently monitored by MS2. The SRM transitions for lab,
Wa and We were m/z 533->435, 423->205 and 474->256, respectively.
Standard curves ranging from 5 nM to 10 jiM were prepared from stock
and seriallv diluted in matrix for both lab and Wa. Standard curves were
aliquoted in duplicate, extracted with the samples, and injected at the beginning,
middle, and end of the analytical sequence. The standard curves were fitted with a
linear regression weighted by reciprocal concentration 1/x2. Data and
chromatographic peaks were processed and concentrations of standards and
unknowns were quantitated using PEBiosystems Analyst™ 1.1.
In Vitro Methods
(1) Stability of lab in EDTA Blood, Serum and Tris-HCl Buffer
The stability of lab was studied in fresh blood and serum, from rat, dog,
monkey and human (n = 2). The blood was collected in vacutainers containing
KaEDTA (Becton Dickinson, Franklin Lakes, NJ). The serum was collected in
vacutainers containing no anticoagulant. lab was incubated at a starting concentration
of approximately 10 JO.M for 60-90 min at 37°C. Serial samples were taken at the predetermined
times. Aliquots of blood samples (200 |iL) were first mixed with 100 |iL
of water followed by 400 of acetonitrile. The serum samples (50 |iL) were added
into microtauiers containing KaEDTA (Becton Dickinson, Franklin Lakes, NJ)
followed by the addition of 100 |0,L of acetonitrile. The supernatant was analyzed for
both lab and FVa by LC/MS/MS.
The stability of lab was also evaluated, as described above, in Tris-HCl buffer
(0.1M,pH7.5).
(2) Hydrolysis of lab in the Presence of Human Placenta! ALP
Solid human placental ALP was obtained from Sigma (P-3895, St. Louis,
MO). A solution of 1000 units/L was prepared in Tris-HCl buffer (0.1 M, pH 7.5).
Solutions of 100 and 10 units/L were obtained by serial dilution. lab was incubated
in the 10, 100 and 1000 units/L solutions (n = 2) at 37°C for 2 hr. The starting
concentration of lab in the incubation was 10 µM. Aliquots of 100 [iL samples were
taken at pre-determined tunes and added into KaEDTA microtainers followed by the
addition of 200 \iL of acetonitrile. The supernatant was analyzed for both lab and
IVa by LC/MS/MS.
In Vivo Studies
All blood samples (0.3 mL) were colleted in microtainers containing KaEDTA
(Becton Dickinson, Franklin Lakes, NJ) and placed on chipped ice. After
centrifugation, plasma was separated and stored at -20°C until analysis. The monolysine
salt of lab (Form 3, Lot 1) was used for the pharmacokinetic studies. The
dosing solutions of lab were prepared in either sterile water (for IV administration in
dogs and monkeys) or distilled water (for all other dose administration).
(1) In Vivo Studies in the Rat
Male Sprague-Dawley rats (300-350 g, Hilltop Lab Animals, Inc., Scottsdale,
PA) with cannulas implanted in the jugular vein were used. The rats were fasted
overnight in the PO pharmacokinetic studies. Blood samples were collected from the
jugular vein.
In the TV study, lab was delivered at 1.4 mg/kg (free acid, or 1.1 mg/kg of IVa
equivalent) as a bolus over 0.5 min (n — 3). The concentration of the dosing solution
was 1.4 mg/mL, and the dosing volume was 1 mL/kg. Serial blood samples were
collected before dosing and at 2, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after
dosing.
In the PO study, lab was administered at 7.9 mg/kg (free acid, or 6.3 mg/kg of
IVa equivalent) by oral gavage (n — 3). The concentration of the dosing solution was
4.0 mg/mL, and the dosing volume was 2 mL/kg. Serial blood samples were
collected before dosing and at 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
(2) In Vivo Studies in the Dog
The IV and PO studies of lab were conducted in a crossover fashion in three
male beagle dogs (11 ± 1.1 kg, Marshall Farms USA Inc., North Rose, NY). There
was a two-week washout period between the IV and PO studies.
hi the W study, lab was infused via the cephalic vein at 1.2 mg/kg (free acid,
or 0.95 mg/kg of IVa equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.4 mg/rnL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10,15, 30, 45 min, 1, 2,4, 6, 8 and 24 hr after dosing.
In the PO study, the dogs were fasted overnight before dosing. lab was
administered by oral gavage at 6.6 mg/kg (free acid, or 5.2 mg/lcg of IVa equivalent).
The concentration of the dosing solution was 13.2 mg/mL, and the dosing volume
was 0.5 mL/kg. Serial blood samples were collected before dosing and at 15, 30, 45
min, 1, 2, 4, 6, 8 and 24 hr after dosing.
To study the effect of food on the oral absorption of IVa after administration
of lab and IVa, these two compounds were administered in capsules as solid to a
group of three dogs in a cross-over fashion under overnight fasting and fed
conditions. There was a one-week washout period between each study. lab was
administered at 200 mg per dog (ca 20 mg/kg) of IVa equivalent; IVa was
administered in a clinical capsule formulation at 200 mg per dog (ca 20 mg/kg). In
the studies where the dogs were fed, the following meal was prepared: 2 slices of
bacon, 2 eggs, 2 pieces of toast with butter and jelly, 4 oz. hash browns and 8 oz. of
whole milk. After homogenization using a laboratory blender, the meal was equally
divided into five portions and kept frozen. Before the study, the meals were thawed
and each dog was fed one portion.
Additional formulation studies of IVa were conducted in fasted dogs (n = 2
per dose group). The dogs were administered either the clinical form or the spray
dried form of IVa in capsules. The clinical capsule form of IVa was administered at a
single dose of 20 mg/kg. The spray dried form of IVa was administered at 20, 75 and
200 mg/kg.
(3) In Vivo Studies in the Monkey
The IV and PO studies of lab were conducted in a crossover fashion in three
male cynomolgus monkeys (11 + 1.2 kg, Charles River Biomedical Research
Foundation, Houston, TX). There was a two-week washout period between the W
and PO studies.
In the IV study, lab was infused via the femoral vein at 1.3 mg/kg (free acid,
or 1.1 ing/kg of IVa equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.6 mg/mL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
In the PO study, the monkeys were fasted overnight before dosing. lab was
administered by oral gavage at 7.1 mg/kg (free acid, or 5.6 mg/kg of IVa equivalent).
The concentration of the dosing solution was 14.2 mg/mL, and the dosing volume
was 0.5 mL/kg. Serial blood samples were collected before dosing and at 15, 30, 45
min, 1 , 2, 4, 6, 8 and 24 hr after dosing.
(4) Data Analysis
All results are expressed as mean ± SD, unless specified otherwise.
The pharmacokinetic parameters of lab and IVa were calculated by Non-
Compartmental Analysis using the KINETICA™ software program (version 4.0.2,
InnaPhase Co., Philadelphia, PA). The Cmax and Tmax values were recorded
directly from experimental observations. The AUCO-n and AUCtot values were
calculated using the mixed log-linear trapezoidal summations. The total body
clearance (Cl), mean residence time (MR.T), and the steady state volume of
distribution (Vss) were also calculated after intravenous administration. The absolute
oral bioavailability (expressed as %) was estimated by taking the ratio of dosenormalized
AUC values after oral doses to those after intravenous doses.
The hepatic clearance QH was calculated from the following equation using
the well-stirred model:
Oh x Cl'mtjn vivo
C1H (mL/min/kg) =
where Qh is the liver blood flow of 55, 31, 44 and 21 mL/min/kg for the rat, dog,
monkey and human, respectively (Davis and Morris, 1993).
The hepatic extraction ration (ER) was calculated at follows:
ClH/Qh
CE) Student's t-test was used for statistical analysis (Microsoft Excel, Redmond, WA).
Differences were considered statistically significant at the level of P In Vitro Studies
Stability of lab in EDTA Blood, Serum and Tris-HCl Buffer
As part of the analytical assay validation, the stability of lab was studied in
blood containing EDTA, which is known to be an inhibitor of alkaline phosphatases
(Bowers, Jr. and McComb, 1966; Yora and Sakagishi, 1986). After incubation at
37°C for 60 min, there was 12% conversion from the initial concentration of lab to
IVa in the rat blood (Table 15), and less than 1% conversion in the monkey and
human blood (Tables 15 and 16). There was approximately 6% conversion in the dog
blood, and the percentages of conversion were similar between two different dogs, as
well as in the same dog on two different test occasions (Tables 15 and 16). Under the
sample storage condition of-20°C, the above small percentages of conversion
observed at 37°C are not expected to introduce any significant ex vivo conversion
during the analysis of lab.
lab was stable in the Tris-HCl buffer at 37°C during the 60-mui study period
(Table Removed)
To investigate the hydrolysis of lab in the systemic circulation, lab was
incubated in fresh serum (rat, dog, monkey and human) at 37°C for 90 min. The rate
of hydrolysis was the most rapid in the rat serum, followed by dog, monkey and
human sera (Table 18). The conversion of lab to IVa was near stoichiometric.
Serum contains lower ALP activities as compared to tissues (McComb et a
1979a). In addition, serum also contains ALP isoforms from tissue sources such as
bone, liver and intestine, which are attributed to leakage through the blood vessels
(Moss, 1983). Therefore, the hydrolysis of lab in serum was probably mediated by
multiple isoforms of ALP.
(Table Removed)
Hydrolysis of lab in the Presence of Human Placenta ALP
To study the hydrolysis of lab in a purified form of human ALP, lab was
incubated in human placental ALP solutions at 10, 100 and 1000 units/L at 37°C for
2 hr. The disappearance ti/? of lab was determined and reported in Table 19. As
expected, the rate of hydrolysis was faster in the solutions with higher ALP activities.
IVa was also formed accordingly (Fig. 8). This indicates that lab is hydrolyzed by the
ALP derived from humans to form IVa.
(Table Removed)
In Vivo Studies in the Rat.
The pharmacokinetic parameters of lab and IVa in rats after IV and oral
administration of lab are summarized in Table 20. The plasma concentration versus
time profiles are shown in Figure 9. For comparison, the historical data from the
pharmacokinetic studies of IVa in rats are also shown.
The total body clearance (Cl) of lab following IV administration was 14
rnL/min/kg, suggesting that lab is a low clearance compound in rats. The elimination
half-life (ti/a) and mean residence time (MRT) after TV administration were 0.16 hr
and 0.14 hr, respectively. lab was not detected beyond 2 hr. The volume of
distribution of lab at steady state (Vss) was 0.12 L/kg, suggesting very limited tissue
distribution. The formation of IVa from lab after IV administration was rapid; IVa
was detected at the first sampling time point of 2 min (data not shown). The TV AUC
ratio of IVa formed from lab vs. from the historical IVa study was 1.5 (theoretical
value for complete conversion = 1), suggesting complete conversion of lab to IVa.
With the exception of one sample (5 nM; Table 20), lab was not detected hi
any samples after oral administration. The Tmax of IVa after oral administration of
lab was 0.83 hr, which is shorter than the historical Tmax of IVa of 2.0 hr, indicating
more rapid absorption of IVa following the oral administration of the prodrug. The
more rapid absorption of IVa from the prodrug is likely the result of better aqueous
solubility of lab as well as rapid hydrolysis of lab to form IVa in the intestine.
Although the absolute oral bioavailability of IVa from lab was 62%, lower than the
historical IVa data, the exposure of IVa from the lab rat oral dose escalation study
was superior as compared to the historical data with TVa (Table 16 and Fig. 8).
The terminal plasma concentration vs. time profiles of IVa formed from lab
are similar to the historical IVa profiles.
(Table Removed)
The pharmacokinetic parameters of lab and IVa in dogs after IV and oral
administration of lab are summarized in Table 21. The plasma concentration versus
time profiles are shown in Figure 10. For comparison, the historical data from the
pharmacokinetic studies of IVa in dogs are also shown.
The Cl of lab after IV administration was 70 mL/min/kg, which is
significantly higher than the liver blood flow of 31 mL/min/kg in dogs, suggestive of
potential involvement of extrahepatic hydrolysis and/or other route(s) of elimination
(e.g., renal excretion). The ti/2 and MRT after IV administration were 0.15 hr and
0.07 hr, respectively. lab was not detected beyond 45 min. The Vss of lab was 0.30
L/kg, suggesting low potential for tissue distribution. The formation of IVa from lab
after IV administration was rapid; IVa was detected at the first sampling time point of
5 min (data not shown). The FV AUC ratio of IVa formed from lab vs. from the
historical IVa study was 0.80, suggesting good conversion of lab to FVa.
lab was detected at 5 nM (LLQ) only at 15 min and 30 min in one dog after
oral administration. The Tmax of IVa after oral administration of lab was 0.25 hr,
which is shorter than the historical Tmax of IVa of 2.9 hr, indicating more rapid
absorption of IVa following the oral administration of the prodrug. The absolute oral
bioavailability of IVa from lab was 94%, higher than the historical IVa data of 57%.
The terminal plasma concentration vs. time profiles of IVa formed from lab are
similar to the historical IVa profiles.
(Table Removed)
To study the effect of food on the oral absorption of IVa after administration
of lab and IVa, the dogs were administered either lab or IVa in capsules under fasting
and fed conditions. The study was conducted in a cross-over fashion, with a oneweek
washout period between each study. No significant differences in the AUC and
Cmax were observed between the fasting and fed conditions after administration of
lab (Table 22), whereas a 9-fold improvement in AUC and Cmax was observed after
administration of IVa with feeding (Table 23). Overall, the effect of feeding was
more pronounced in dogs (Table 23) than in human subjects (Table 24) receiving
IVa. This is suggestive of quantitative species differences in the effect of food on the
oral absorption of IVa.
The oral absorption of IVa was shown to be dissolution-rate limited in
humans and animal species. The improvement of IVa exposure in humans upon
feeding with a high fat meal was presumably due to the increased secretion of bile
salts which facilitated the dissolution of IVa. In dogs, the lack of the effect of food
on the oral absorption of IVa after lab administration suggests potential benefits in
humans, for whom diet modification may not be required.
(Table Removed)
(Table Removed)
Additional capsule formulation studies were conducted in the same fasted
dogs with the clinical and spray dried forms of IVa to compare with lab. As shown hi
Table 25, at 20 mg/kg of IVa equivalent, similar exposure of IVa was observed
following administration of lab and the spray dried form of IVa. However, lab
provided significantly higher exposure of IVa as compared to the clinical form of
IVa. The AUC and Cmax of IVa from the prodrug were 37 times and 45 times
higher, respectively, than the values from the clinical form of IVa. The fold increase
in dogs is likely an over-prediction of the clinical situation based on the experience
with FVa in development (data not shown).
hi the dose escalation study of the spray-dry form of IVa in dogs, the increases
of AUC and Cmax from 20 mg/kg to 75 mg/kg were less than proportional to dose
increase (Table 26). No significant further increases in exposure were observed from
75 mg/kg to 200 mg/kg.
(Table Removed)
time profiles are shown in Figure 11. For comparison, the historical data from the
pharmacokinetic studies of IVa in monkeys are also shown.
The Cl of lab after IV administration was 4.4 mL/min/kg, suggesting that lab
is a low clearance compound in monkeys. The ti/2 and MRT after IV administration
were 1.0 hr and 0.18 hr, respectively. The MRT reflected a more realistic estimate of
the duration of lab in the plasma since the plasma concentrations of lab in the
terminal phase were low (Fig. 11). lab was not detected beyond 6 hr. The Vss of lab
was 0.048 L/kg, suggesting very limited tissue distribution. The formation of IVa
from lab after IV administration was rapid; IVa was detected at the first sampling
time point of 5 min (data not shown). The TV AUC ratio of IVa formed from lab vs.
from the historical IVa study was 0.70, suggesting good conversion of lab to IVa.
lab was detected at a concentration of 18 nM at 15 min in only one monkey
after oral administration. The Tmax of IVa after oral administration of lab was 0.83
hr, which is shorter than the historical Tmax of IVa of 2.7 hr, indicating more rapid
absorption of IVa following the oral administration of the prodrug. The absolute oral
bioavailability of IVa from lab was 66%, similar to the historical IVa data of 60%.
The terminal plasma concentration vs. time profiles of IVa formed from lab
are similar to the historical IVa profiles.
(Table Removed)
IV and PO pharmacokinetic studies of Ibb were conducted in rats, dogs and
monkeys. In all cases, blood samples were collected in the presence of EDTA. The
presence of EDTA, a known ALP inhibitor, minimized significant ex vivo conversion
of Ibb during sample processing. IVb was rapidly formed following IV
administration of Ibb. Good oral bioavailabilities of IVb (50-310%; calculated using
the historical IV AUC of IVb) were observed after administration of Ibb in rats, dogs
and monkeys with very low levels of Ibb present in plasma. Since there are high
levels of ALP expression in the gut, it is likely that following oral administration of
Ibb, Ibb is hydro lyzed by ALP present at the brash border membranes of the intestinal
lumen to form IVb, which is rapidly absorbed due to its high permeability.
In vitro incubation studies were conducted for a qualitative assessment of
ALP-dependent hydrolysis of Ibb in different tissues. Ibb was hydrolyzed in the
presence of serum and hepatocytes from rat, dog, monkey and human, as well as
human placental ALP. On the occasions where Ibb and IVb were measured, the
conversion of Ibb to IVb was near stoichiometric. Due to hydrolysis in serum, the
protein binding of Ibb could not be determined. Based on the in vitro data, it is
anticipated that Ibb will be hydrolyzed by human ALP and that IVb will be formed
after oral administration of Ibb to human subjects.
The crystalline solubility of Ibb-03 at room temperature is >11 mg/mL in the
pH range of 1.5 to 8.7; aqueous solutions containing >75 mg/mL have been prepared
for in vivo toxicology studies, hi comparison, the aqueous solubility of the parent
compound, IVb, at room temperature as crystalline material was determined to be
0.007 - 0.19 mg/mL (pH range of 1.0 - 9.6). Ibb-03 exhibits acceptable solution and
solid stabilities.
The higher aqueous solubility of Ibb provides a means to overcome the
dissolution-rate limited absorption of IVb below certain doses and thereby increased
the exposures of IVb in oral dose escalation and toxicokinetic studies. Ibb, when
dosed orally up to 200 mg/kg of IVb bmsequivalent, provided 11- and 2.6-fold (BID)
higher AUC of FVb in rats and dogs, respectively, with relatively low plasma
exposure to the prodrug ( suspension studies at the similar dose.
Single-Dose Toxicokinetic Study in Spragne Dcnvley Rats
A 1-day oral toxicokinetic study in rats was conducted by using the prodrug
Ibb (monolysine salt). Ibb was administered at dosages of 19, 64, and 236 mg/kg
(free acid) by oral gavage to three male rats/group using water as the vehicle (solution
formulation). The dosages of prodrug free acid correspond to IVb (parent) molar
equivalent dosages of 15, 51, and 190 mg/kg, respectively. The endpoint evaluated
was plasma toxicokinetics of Ibb and IVb in the individual rats.
The mean toxicokinetic values are provided in Table 28.
(Table Removed)
Mean maximum plasma concentration (Cmax) of IVb (parent) was achieved
within ~l-3 hours post-dose. In rats given IVb was nearly proportional with Ibb dosage, and Cmax increased in a less than
dosage-proportional manner between 19 and 236 mg/kg of Ibb. Ibb was detected in
plasma of rats given 19 mg/kg of Ibb but at very low concentrations relative to those
A comparison of IVb Cmax and AUC obtained in rats given either IVb or Ibb,
is shown in Figure 12.
The exposure to IVb is substantially increased following administration of Ibb
compared to that achieved after dosing FVb.
Single-Dose Toxicokinetic and Tolerability Study in Dogs
A two-phase study was conducted to evaluate the tolerability of the prodrug,
Ibb (monolysine salt) at dosages of 25, 92, or 250 nig/leg (free acid, molar equivalent
to 20, 74, or 201 mg/kg of parent IVb, respectively) and the toxicokinetics of Ibb and
IVb (1). On day 1, Ibb was administered to one dog/sex/group once daily in dryfilled
capsules at the above dosages. A 1-week washout period was used between
doses in the study. On day 8, Ibb was administered to one dog/sex/group once daily
as an aqueous solution at 25 mg/kg or twice daily in dry-filled capsules at 46 or 125
mg/kg BID. The endpoints were: clinical signs, body weight, food consumption,
serum chemistry, hematology and plasma toxicokinetics of Ibb and IVb.
The plasma toxicokinetic values from individual dogs are shown in Table 29.
(Table Removed)
were detected in some plasma samples on days
1 and 8. Mean maximum plasma concentration (Cmax) of IVb was achieved between
1-4 hours post-dose for QD dosing, and 1-2 hours post-second dose for BID dosing.
At 25 mg/kg QD, equivalent Cmax and AUC of IVb was observed when Ibb was
administered as either dry-filled capsules or an aqueous solution. On day 1, emesis
(white, streaked with red that contained capsule remnants) was observed at about 0.5-
1.25 hours after dosing in all dogs given 92 mg/kg QD (3101M, 3201F, 4101M, and
4201F), which likely contributed to the flat exposure between 92 and 250 mg/kg. On
day 8, emesis (white or brown) was observed within 2 hours after dosing in all dogs
given >46 mg/kg BID; capsule remnants were only observed in vomitus of two dogs
(3101M post-first dose and 420IF post second dose). Twice-daily dosing provided
greater exposure to IVb in dogs than once daily dosing.
Other than emesis, there were no clinical signs observed, and there were no
effects on body weight and food consumption.
Despite the emesis observed in dogs, a higher IVb AUC is observed in dogs
given Ibb than that in dogs given IVb. A comparison of IVb AUC obtained in dogs
given either Ibb or IVb (2), is shown in Figure 13.
The absolute oral bioavailability of IVb, parent compound, after
administration of aqueous solutions of Ibb-03, the phosphate prodrug, ranged from
50% to 310% in rats, dogs, and monkeys. These calculations are based on historical
IV data. The exposure of FVb, after oral administration of aqueous solutions of the
prodrug, Ibb-03, dosed up to 190 mg/kg of IVb equivalent is 3-10 fold higher in the
rat oral dose escalation study as compared to the historical data with TVb. When Ibb-
03 is dosed BID as drug in capsule in dogs, 2-3 fold improvement in exposure is
achieved compared to historical data from pre-ECN toxicology studies with BID
dosing of IVb as suspensions. The in vivo exposure data from drug in capsule
formulations suggests that oral exposure of IVb in humans could be significantly
improved by administration of traditional solid oral dosage forms of Ibb.
Ibb is the phosphate prodrug of the N-hydroxymethyl adduct of IVb and is
hydrolyzed by alkaline phosphatase (ALP) to form IVb. After administration of Ibb
to animals, therefore, plasma samples were prepared from blood collected iri the
presence of EDTA, a known ALP inhibitor. Conversion of Ibb to IVb was minimal
( ex vivo conversion of Ibb is expected during sample storage (-20°C) and analysis of
Ibb.
The hydrolysis of Ibb was studied in animal and human in vitro systems.
Since multiple ALP isoforms are widely distributed in various tissues, quantitative in
vitro to in vivo correlations were not attempted (Fishman et al., 1968; Komoda et al.,
1981; Moss, 1983; Yora and Sakagishi, 1986; Sumikawa et al., 1990). Therefore, the
studies were limited to a qualitative assessment of ALP-dependent hydrolysis in
different tissues. Ibb was hydrolyzed in the presence of serum (rat, dog, monkey and
human), hepatocytes (rat, dog and human) as well as in human placental ALP. No
turnover was observed in monkey hepatocytes. The conversion of Ibb to IVb was
near stoichiometric. Due to hydrolysis in serum, the protein binding of Ibb could not
be determined.
Ibb was completely hydrolyzed to form IVb in Caco-2 cells and, as expected,
very low levels of Ibb were detected in rat, dog and monkey plasma after oral
administration of Ibb. These data are consistent with reports describing the high
levels of ALP expression in the gut (McComb et al, 1979a; Butterworth, 1983). The
membrane-bound ALP is mostly localized in the brush border membranes of the
microvilli lining the intestinal lumen (Butterworth, 1983; Testa and Mayer, 2003). It
is likely that following oral administration of Ibb, Ibb is hydrolyzed by ALP present at
the brush border membranes of the intestinal lumen to form IVb, which is rapidly
absorbed due to its high permeability.
Although different isoforms of ALP exist in different tissues and species, the
substrate specificity for ALP is relatively broad (Heimbach et al., 2003), which is
consistent with the above findings for Ibb.
IVb was rapidly formed following IV administration of Ibb in rats, dogs and
monkeys. The IV AUC conversion ratios were 0.62 in rats, 1.6 in dogs and 1.7 in
monkeys, suggesting satisfactory to good conversion from Ibb to IVb.
Good oral bioavailabilities (50-310%; calculated using the historical IV AUC
of IVb) of IVb were observed after administration of Ibb in rats, dogs and monkeys.
More significantly, the higher aqueous solubility of Ibb lessened the dissolution-rate
limited absorption of IVb and thereby increased the exposures of IVb in oral dose
escalation and toxicokinetic studies as compared to the exposures from the historical
IVb studies (Discovery Toxicology section Tables 28-29 and Fig. 12-13).
Methods
The studies described in this report used the mono-lysine salt of Ibb.
Quantitation of Ibb and IVb by L C/MS/MS
An LC/MS/MS method was developed for the analysis of Ibb and IVb in
plasma samples from the animal pharmacokinetic studies as well as in acetonitrile
supernatant from in vitro incubation studies. For the analysis in plasma, a Packard
Multiprobe instrument was used to transfer 50 of each standard, QC, and plasma
sample to a clean 96-well plate for protein precipitation extraction. After the addition
of 200 [4.L of acetonitrile containing the internal standard We, the samples were
vortex mixed and the resulting supernatant was separated from the precipitated
proteins by centrifugation for 10 min. For the analysis in the supernatant generated
from the in vitro studies, an equal volume of the supernatant and acetonitrile
containing the internal standard was mixed. An aliquot of the above supernatant was
transferred using a Tomtec automated liquid handler to a second clean 96-well plate.
An equal volume of water was added, and the plate was capped and vortex mixed.
The HPLC system consisted of Shimadzu LClOADvp pumps (Columbia,
MD) and a HTC PAL autosampler (Leap Technologies, Gary, NC) linked to a
Phenomenex Synergi Fusion-RP analytical column (2.0 x 50 mm, 5 |i; Torrance,
CA). Mobile phase A consisted of 5 mM ammonium formate in water; mobile phase
B was 100% acetonitrile. LC flow rate was 0.38 mL/min. The initial mobile phase
composition was 2% B, ramped to 50% B over 1.8 min and held for 0.5 min, ramped
to 100% B over 0.1 min and held for 0.5 min, returned to initial conditions over the
next 0.1 min, and re-equilibrated. Total analysis time was 4.0 min. The retention
time for Ibb, IVb and IVc was 1.42, 2.21 and 1.73 min, respectively.
The HPLC system was interfaced to a Sciex API4000 triple quadrupole mass
spectrometer (Toronto, Canada) equipped with the Turboionspray source set at 550°C
and the ionspray voltage set to 4.5 kV. UHP nitrogen was used as nebulizer and
auxiliary gas with the pressure of 80 psi and 7-L/min, respectively. The collision
energies for Ibb, IVb and IVc were 19, 25 and 29 volts, respectively. Data acquisition
utilized selected reaction monitoring (SRM). Ions representing the positive ion mode
(M+H) species for Ibb, IVb and the internal standard were selected in MSI and
collisionally dissociated with nitrogen and optimized collision energies to form
specific product ions subsequently monitored by MS2. The SRM transitions for Ibb,
IVb and IVc were 777/2 558->432, 448->202 and 474->256, respectively.
Standard curves ranging from 5 nM to 10 |iM were prepared from stock
solutions and serially diluted in matrix for both Ibb and IVb. Standard curves were
aliquoted in duplicate, extracted with the samples, and injected at the beginning,
middle, and end of the analytical sequence. The standard curves were fitted with a
linear regression weighted by reciprocal concentration 1/x2. Data and
chromatographic peaks were processed and concentrations of standards and
unknowns were quantitated using PEBiosystems Analyst™ 1.1.
In Vitro Methods
(1) Stability of Ibb in EDTA Blood, Serum and Tris-HCl Buffer
The stability of Ibb was studied in fresh blood and serum from rat, dog,
monkey and human (n — 2). The blood was collected in vacutainers containing
KiEDTA (Becton Dickinson, Franklin Lakes, NJ). The serum was collected in
vacutainers containing no anticoagulant. Ibb was incubated at a starting
concentration of approximately 15 for 90 min at 37°C. Serial samples were taken
at the pre-determined times. Aliquots of blood samples (200 ^iL) were first mixed
with 100 jiL of water followed by 400 uJL of acetonitrile. The serum samples (50
were added into microtainers containing KEDTA (Becton Dickinson, Franklin
Lakes, NJ) followed by the addition of 100 pL of acetonitrile. The supernatant was
analyzed for both Ibb and IVb by LC/MS/MS.
The stability of Ibb was also evaluated, as described above, in Tris-HCl buffer
(0.1M,pH7.5).
(2) Hydrolysis of Ibb in the Presence of Human Placenta! ALP
Solid human placental ALP was obtained from Sigma (P-3895, St. Louis,
MO). A solution of 1000 units/L was prepared in Tris-HCl buffer (0.1 M, pH 7.5).
Solutions of 100 and 10 units/L were obtained by serial dilution. Ibb was incubated
in the 10, 100 and 1000 units/L solutions (n = 2) at 37°C for 2 hr. The starting
concentration of Ibb in the incubation was 10 pM. Aliquots of 100 |jJL samples were
taken at pre-determined times and added into KaEDTA microtainers followed by the
addition of 200 jiL of acetonitrile. The supernatant was analyzed for both Ibb and
IVbbyLC/MS/MS.
In Vivo Studies
All blood samples (0.3 rnL) were colleted in microtainers containing
K^EDTA (Becton Dickinson, Franklin Lakes, NJ) and placed on chipped ice. After
centrifugation, plasma was separated and stored at -20°C until analysis. The monolysine
salt of Ibb (Form 3) was used for the pharmacokinetic studies. The dosing
solutions of Ibb were prepared in either sterile water (for IV administration in dogs
and monkeys) or distilled water (for all other dose administration).
(1) In Vivo Studies in the Rat
Male Sprague-Dawley rats (300-350 g, Hilltop Lab Animals, Inc., Scottsdale,
PA) with cannulas implanted in the jugular vein were used. The rats were fasted
overnight in the PO pharmacolcinetic studies. Blood samples were collected from the
jugular vein.
hi the IV study, Ibb was delivered at 1.3 mg/lcg (free acid, or 1.0 mg/kg of FVb
equivalent) as a bolus over 0.5 min (n = 3). The concentration of the dosing solution
was 1.3 mg/mL, and the dosing volume was 1 mL/lcg. Serial blood samples were
collected before dosing and at 2, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after
dosing.
In the PO study, Ibb was administered at 6.6 mg/kg (free acid, or 5.2 mg/kg of
IVb equivalent) by oral gavage (n = 3). The concentration of the dosing solution was
1.3 mg/mL, and the dosing volume was 5 mL/kg. Serial blood samples were
collected before dosing and at 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
(2) In Vivo Studies in the Dog
The IV and PO studies of Ibb were conducted in male beagle dogs (10 + 0.78
kg, Marshall Farms USA Inc., North Rose, NY). Three dogs were used in each study.
Of the three dogs, two same dogs were used for both IV and PO studies. There was a
two-week washout period between the IV and PO studies.
In the IV study, Ibb was infused via the cephalic vein at 1.3 mg/kg (free acid,
or 1.0 mg/kg of IVb equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.6 mg/mL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
hi the PO study, the dogs were fasted overnight before dosing. Ibb was
administered by oral gavage at 7.0 mg/kg (free acid, or 5.6 mg/kg of IVb equivalent).
The concentration of the dosing solution was 7.0 mg/mL, and the dosing volume was
1 mL/kg. Serial blood samples were collected before dosing and at 15, 30,45 min, 1,
2, 4, 6, 8 and 24 hr after dosing.
(3) In Vivo Studies in the Monkey
The IV and PO studies of ]bb were conducted in a crossover fashion in three
male cynomolgus monkeys (9.9 ± 2.4 kg, Charles River Biomedical Research
Foundation, Houston, TX). There was a two-week washout period between the IV
andPO studies.
hi the IV study, Ibb was infused via the femoral vein at 1.3 mg/kg (free acid,
or 1.1 mg/kg of PVb equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.7 mg/mL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
In the PO study, the monkeys were fasted overnight before dosing. Ibb was
administered by oral gavage at 5.8 mg/kg (free acid, or 4.7 mg/kg of FVb equivalent).
The concentration of the dosing solution was 5.8 mg/rnL, and the dosing volume was
1 mL/kg. Serial blood samples were collected before dosing and at 15, 30, 45 min, 1,
2, 4, 6, 8 and 24 hr after dosing.
(4) Data Analysis
All results are expressed as mean ± SD, unless specified otherwise.
The pharmacokinetic parameters of Ibb and IVb were calculated by Non-
Compartmental Analysis using the KTNETICA™ software program (version 4.0.2,
InnaPhase Co., Philadelphia, PA). The Cmax and Tmax values were recorded
directly from experimental observations. The AUCo-n and AUCtot values were
calculated using the mixed log-linear trapezoidal summations. The total body
clearance (Cl), mean residence time (MRT), and the steady state volume of
distribution (Vss) were also calculated after intravenous administration. The absolute
oral bioavailability (expressed as %) was estimated by taking the ratio of dosenormalized
AUC values after oral doses to those after intravenous doses.
The in vitro intrinsic clearance of Ibb in hepatocytes (Cljnt) was calculated as
follows:
Cljnt (M-L/min/million cells) = Rate / CE
where Rate is the rate of metabolism in hepatocytes (pmol/min/million cells), and CE
is the concentration of Ibb in the incubation.
where % is 40, 32, 30 and 26 g liver/kg body weight for the rat, dog, monkey and
human, respectively (Davis and Morris, 1993).
The hepatic clearance QH was calculated from the following equation using
the well-stirred model:
C1H (mL/min/kg) n
where Qh is the liver blood flow of 55, 31, 44 and 21 rnL/min/kg for the rat, dog,
monkey and human, respectively (Davis and Morris, 1993).
The hepatic extraction ration (ER) was calculated at follows:
j Student's t-test was used for statistical analysis (Microsoft Excel, Redmond, WA).
Differences were considered statistically significant at the level of P In Vitro Studies
Stability of Ibb in EDTA Blood, Serum and Tris-PICl Buffer
As part of the analytical assay validation, the stability of Ibb was studied in
blood containing EDTA, which is known to be an inhibitor of ALP (Bowers, Jr. and
McComb, 1966; Yora and Sakagishi, 1986). After incubation at 37°C for 90 min,
there was less than 2% conversion of Ibb to IVb in blood containing EDTA and in the
presence of Tris-HCl buffer (Tables 30 and 31). The above small percentages of
conversion observed at 37°C indicate that conversion under the sample storage
conditions (-20°C) is unlikely. Therefore, relatively minimal ex vivo conversion to
IVb is expected during the analysis of Ibb.
(Table Removed)
To investigate the hydrolysis oflbb in the systemic circulation, Ibb was
incubated in fresh serum (rat, dog, monkey and human) at 37°C for 90 min. The rate
of hydrolysis was most rapid in the monkey serurn, followed by human, dog and rat
sera (Table 3). The conversion oflbb to .IVb was near stoichiometric.
Serum contains lower ALP activities as compared to tissues (McComb et al,
1979a). hi addition, serum also contains ALP isoforms from tissue sources such as
bone, liver and intestine, as a result of enzyme leakage through the blood vessels
(Moss, 1983). Therefore, the hydrolysis of Ibb in serum was probably mediated by
multiple isoforms of ALP.
(Table Removed)
To study the hydrolysis of Ibb in a purified form of human ALP, Ibb was
incubated at 37°C (2 hr) with solutions containing human placental ALP (10, 100 and
1000 units/L). The disappearance ti/2 of Ibb was determined (Table 4). As expected,
the rate of hydrolysis was faster in the solutions with higher ALP activities. IVb was
also formed accordingly (Fig. 1 4). This indicates that Ibb is hydrolyzed by the ALP
derived from humans to form IVb.
(Table Removed)
The pharmacokinetic parameters of Ibb and TVb in rats after IV and oral
administration of Ibb are summarized in Table 34. The plasma concentration versus
time profiles are shown in Figure 15. For comparison, the historical data from the
pharmacokinetic studies of IVb in rats are also shown.
The total body clearance (Cl) of Ibb following IV administration was 19
mL/min/kg, suggesting that Ibb is a low to moderate clearance compound in rats. The
elimination half-life (ti/2) and mean residence time (MRT) after IV administration
were 0.18 hr and 0.079 hr, respectively. lab was not detected beyond 2 hr. The
volume of distribution of Ibb at steady state (Vss) was 0.10 L/kg, suggesting very
limited tissue distribution. The formation of IVb from Ibb after IV administration
was rapid; IVb was detected at the first sampling time point of 2 min (data not
shown). The IV AUC ratio of IVb formed from Ibb vs. from the historical IVb study
was 0.62 (theoretical value for complete conversion = 1), indicating satisfactory
conversion of Ibb to IVb in rats after IV dosing.
Ibb was detected ( administration. The Tmax of IVb after oral administration of Ibb was 0.83 hr, which
is shorter than the historical Tmax of IVb of 4.7 hr, indicating more rapid absorption
of IVb following the oral administration of the prodrug. The more rapid absorption
of IVb from the prodrug is likely the result of better aqueous solubility of Ibb as well
as rapid hydrolysis of Ibb to form IVb in the intestine. The absolute oral
bioavailability of IVb from Ibb was 50%, similar to the historical IVb value of 60%
(Table 34). Moreover, the exposure of IVb from the Ibb rat oral dose escalation study
was superior as compared to the historical data with IVb (Table 31 and Fig. 14).
(Table Removed)
time profiles are shown in Figure 16. For comparison, the historical data from the
pharmacokinetic studies of IVb in dogs are also shown.
The Cl of Ibb after IV administration was 27 mL/min/kg, similar to the liver
blood flow of 31 mL/min/kg in dogs, suggesting that Ibb is a high clearance
compound in dogs. The t\/2 and MRT after IV administration were 0.83 hr and 0.21
hr, respectively. The MRT reflected a more realistic estimate of the duration of Ibb in
the plasma since the plasma concentrations of Ibb in the terminal phase were low
(Fig. 3). Ibb was not detected beyond 4 hr. The Vss of Ibb was 0.35 L/kg, suggesting
limited tissue distribution. The formation of IVb from Ibb after IV administration
was rapid; FVb was detected at the first sampling time point of 5 min (data not
shown). The IV AUC ratio of IVb formed from Ibb vs. from the historical IVb study
was 1.6, suggesting complete conversion of Ibb to IVb in dogs after IV
administration.
Ibb was detected (Cmax - 0.034 nM) in plasma samples at early time points
(up to 2 hr in one dog) following oral administration. The Tmax of IVb after oral
administration of Ibb was 0.40 hr, similar to the historical Tmax of IVb of 0.50 hr.
The absolute oral bioavailability of IVb from Ibb was 310%, similar to the historical
IVb data of 179%. Moreover, the exposure of IVb from the Ibb dog tolerability study
(dose escalation) was greater when compared to the historical data with IVb (Table
3 land Fig. 15).
The terminal plasma concentration vs. time profiles of IVb formed from Ibb
are similar to the historical IVb profiles (Fig. 16).
(Table Removed)
versus time profiles are shown in Figure 17. For comparison, the historical data from
the pharmacokinetic studies of IVb in monkeys are also shown.
The Cl of Ibb after IV administration was 28 mL/min/kg, suggesting that Ibb
is a moderate to high clearance compound in monkeys. The ty2 and MRT after IV
administration were 0.10 hr and 0.093 hr, respectively. The Vss of Ibb was 0.15
L/kg, suggesting very limited tissue distribution. The formation of IVb from Ibb
after IV administration was rapid; FVb was detected at the first sampling time point of
5 min (data not shown). The IV AUC ratio of IVb formed from Ibb vs. from the
historical IVb study was 1.7, suggesting complete conversion of Ibb to IVb in
monkeys after IV dosing.
Ibb was not detected (LLQ = 5 nM) in any plasma samples after oral
administration. The Tmax of IVb after oral administration of Ibb was 1.5 hr, similar
to the historical Tmax of IVb of 2.5 hr. The absolute oral bioavailability of IVb from
Ibb was 187%, which is higher that the historical IVb data of 49% (Table 36).
The terminal plasma concentration vs. time profiles of IVb formed from Ibb
are similar to the historical IVb profiles (Fig. 17).
(Table Removed)
Profiling Section 3:
Additional Studies with Prodrug Icb
Single-Dose Toxicokinetic Toler ability Study in CD Rats
A 1-day oral toxicokinetic study in rats was conducted using the prodrug Icb
(disodium salt). Icb was administered at dosages of 5, 25, and 200 mg/kg (free acid)
by oral gavage to three male rats/group using water as the vehicle (solution
formulation). The dosages of prodrug free acid correspond to IVc (parent) molar
equivalent dosages of 4.5, 21, and 163 mg/kg, respectively. The endpoint evaluated
was plasma toxicokinctics of Icb and IVc in the individual rats.
The mean toxicokinetic values are provided in Table 37.
(Table Removed)
Mean maximum plasma concentration (Cmax) of IVc (parent) was achieved
within ~1.7 hour post-dose. In rats given IVc was nearly proportional with Icb dosage, and Cmax increased in a less than
dosage-proportional manner between 25 and 200 mg/kg of Icb. Icb was not detected
in plasma of rats given |iM) were detected in plasma of rats given 200 mg/kg of Icb at a few time points.
A comparison of IVc AUC obtained in rats given either IVc (1) or Icb, is
shown in Figure 18.
The AUC of IVc is similar after administration of either parent or prodrag at
lower dosages (e.g., 400/ethanol/0.1N NaOH for parent and water for prodrug) but at a high dosage (e.g.,
200 mg/kg) the neutral parent can only be formulated as a suspension whereas the
prodrug salt can be formulated as an aqueous solution, which provides superior
exposure of IVc.
Single-Dose Toxicokinetic and Tolerability Study in Dogs
A two-phase study was conducted to evaluate the tolerability of the prodrug,
Icb (monotromethamine salt) at dosages of 25, 92, or 250 mg/kg (free acid, molar
equivalent to 20, 75, or 203 mg/kg of parent IVc, respectively) and the toxicokinetics
of Icb and IVc (2). On day 1, Icb was administered to one dog/sex/group once daily
in dry-filled capsules at the above dosages. A 1-week washout period was used
between doses in the study. On day 8, Icb was administered to one dog/sex/group
once daily as an aqueous solution at 25 mg/kg or twice daify in dry-filled capsules at
46 or .125 mg/kg BID. The endpoints were: clinical signs, body weight, food
consumption, serum chemistry, hcmatology and plasma toxicokinetics of Icb and IVc.
The plasma toxicoldnetic values from individual dogs are shown in Table 38.
(Table Removed)
Low levels ( and 8. Mean maximum plasma concentration (Cmax) of IVc was achieved between
1-2 hours post-dose for QD dosing, and 1-2 hours post-second dose for BID dosing.
At 25 mg/kg QD, equivalent Cmax and AUC of IVc was observed when Icb was
administered as either dry-filled capsules or an aqueous solution. On day 1, emesis
(white or brown, streaked with red that contained capsule remnants) was observed at
about 1-1.25 hours after dosing in dogs given 92 mg/kg QD (3101M, 4101M, and
4201F), which likely contributed to the flat exposure between 92 and 250 mg/kg. On
day 8, emesis was observed within 2 hours after dosing in both dogs given 125 mg/kg
BID but with different results. Animal 4101M had substantial exposure despite
emesis, consistent with the absence of capsule remnant in the vomitus.
Only low levels ( days 1 and 8.
Other than emesis, there were no clinical.signs observed, and there were no
effects on body weight and food consumption.
Despite the emesis observed in dogs, a higher IVc AUC is observed in dogs
given Icb than that in dogs given IVc. A comparison of IVc AUC obtained in dogs
given either Icb or .IVc (3, 4), is shown in Figure 19.
Vehicles and Formulations
Summary of Formulations Used for Key PK and Safety Studies
All in vivo PK studies in rats, dogs, and monkeys were performed using
aqueous solutions for PO and IV dosing. Prc-ECN toxicology studies in dogs were
performed with aqueous solutions prepared at 20 mg/kg IVc equivalent dose and as
drug in capsule formulations at doses of 20, 75, and 203 mg/kg of IVc equivalents.
In rat oral dose escalation study, Icb-03 was dosed as aqueous solutions at
doses of 4.5, 21, and 163 mg/kg of IVc equivalents. Significant improvements in
AUC and Cmax of IVc, parent compound, after oral dosing of Icb, the prodrug, were
observed compared to the historical data after IVc oral dosing.
Metabolism and Pharmacokinetics Summary
Summary of Findings and Interpretation
Icb is the phosphate prodrug of the N-hydroxymethyl adduct of IVc and is
hydrolyzed by alkaline phospbatase (ALP) to form IVc. After administration of Icb
to animals, therefore, plasma samples were prepared from blood collected in the
presence of EDTA, a known ALP inhibitor. Conversion of Icb to IVc was minimal
( ex vivo conversion of Icb is expected during sample storage (-20°C) and analysis of
Icb.
The hydrolysis of Icb was studied in animal and human in vitro systems.
Since multiple ALP isoforms are widely distributed in various tissues, quantitative in
vitro to in vivo correlations were not attempted (Fishman et a!., 1968; Komoda et al.,
1981; Moss, 1983; Yora and Sakagishi, 1986; Sumikawa et al., 1990). Therefore, the
studies were limited to a qualitative assessment of ALP-dependent hydrolysis in
different tissues. Icb was hydrolyzed in the presence of serum (rat, dog, monkey and
human), hepatocytes (rat, dog and human) as well as in human placental ALP. No
turnover was observed in monkey hepatocytes. The conversion of Icb to IVc was
near stoichiometric. Due to hydrolysis in serum, the protein binding of Icb could not
be determined.
IVc was rapidly formed following IV administration of Icb in rats, dogs and
monkeys. The IV AUC conversion ratios were 1.0 in rats, 0.67 in dogs and 0.90 in
monkeys, suggesting good conversion from Icb to IVc.
Good oral bioavailabilities (80-122%) of IVc were observed after
administration of Icb in rats, dogs and monkeys. More significantly, the higher
aqueous solubility of Icb lessened the dissolution-rate limited absorption of IVc
below certain doses and thereby increased the exposures of IVc in oral dose
escalation and toxicokinetic studies as compared to the exposures from the historical
IVc studies.
Methods
The studies described in this report used the monotromethamine salt of Icb,
unless stated otherwise.
Quantitation of Icb and We by LC/MS/MS
An LC/MS/MS method was developed for the analysis of Icb and IVc in
plasma samples from the animal pharmacokinetic studies as well as in acetonitrile
supernatant from in vitro incubation studies. For the analysis in plasma, a Packard
Multiprobe instrument was used to transfer 50 pL of each standard, QC, and plasma
sample to a clean 96-well plate for protein precipitation extraction. After the addition
of 200 (J,L of acetonitrile containing the internal standard Compound X below, the
samples were vortex mixed and the resulting supernatant was separated from the
precipitated proteins by centrifugation for 10 min. For the analysis in the supernatant
generated from the in vitro studies, an equal volume of the supernatant and
acetonitrile containing the internal standard was mixed. An aliquot of the above
supernatant was transferred using a Tomtec automated liquid handler to a second
clean 96-well plate. An equal volume of water was added, and the plate was capped
and vortex mixed.
Compound X
4-methoxy-3-(2-oxo-2-(4-(quinazolin-4-yl)piperazin-1-yl)acetyI)-1/-/-
pyrrolo[2,3-c]pyridine-7-carboxamide
The BPLC system consisted of Shimadzu LClOADvp pumps (Columbia,
MD) and a HTC PAL autosampler (Leap Technologies, Gary, NC) linked to a
Phenomenex Synergi Fusion-RP analytical column (2.0 x 50 mm, 5 u,; Torrance, CA).
Mobile phase A consisted of 5 mM ammonium formate in water; mobile phase B was
100% acetonitrile. LC flow rate was 0.4 mL/min. The initial mobile phase
composition was 3% B, ramped to 60% B over 1.75 min and held for 0.5 min,
tn 100% R nver 0.1 min and held for 0.5 min. returned to initial conditions
over the next 0.1 min, and re-equilibrated. Total analysis time was 4.0 rnin. The
retention time for Icb, IVc and Compound X was 1.2, 1.7 and 1.6 min, respectively.
The HPLC system was interfaced to a Sciex AP14000 triple quadrupole mass
spectrometer (Toronto, Canada) equipped with the Turboionspray source set at 550°C
and the ionspray voltage set to 4.5 kV. UHP nitrogen was used as nebulizer and
auxiliary gas with the pressure of 80 psi and 7 L/min, respectively. The collision
energies for Icb, IVc and Compound X were 23, 29 and 37 volts, respectively. Data
acquisition utilized selected reaction monitoring (SRM). Ions representing the
positive ion mode (M+H)+ species for Icb, IVc and the internal standard were selected
in MSI and collisionally dissociated with nitrogen and optimized collision energies to
form specific product ions subsequently monitored by MS2. The SRM transitions for
Icb, IVc and Compound X were m/z 584-^486, 474^256 and 460->218,
respectively.
Standard curves ranging from 5 nM to 10 uJVt were prepared from stock
solutions and serially diluted in matrix for both Icb and IVc. Standard curves were
aliquoted in duplicate, extracted with the samples, and injected at the beginning,
middle, and end of the analytical sequence. The standard curves were fitted with a
linear regression weighted by reciprocal concentration 1/x2. Data and
chromatographic peaks were processed and concentrations of standards and
unknowns were quantitatcd using PEBiosystems Analyst™ 1.1.
In Vitro Methods
(1) Stability of Icb in EDTA Blood, Serum and Tris-HCl Buffer
The stability of Icb was studied in fresh blood and serum from rat, dog,
monkey and human (n = 2). The blood was collected in vacutainers containing
KaEDTA (Becton Dickinson, Franklin Lakes, NT). The serum was collected in
vacutainers containing no anticoagulant. Icb was incubated at a starting concentration
of approximately 10 jLiM for 90 min at 37°C. Serial samples were taken at the predetermined
times. Aliquots of blood samples (200 uJL) were first mixed with 100 jiL
of water followed by 400 uL of acetonirrile. The serum samples (50 |iL) were added
into microtainers containing K?EDTA (Becton Dickinson, Franklin Lakes, NJ)
followed by the addition of 100 jxL of acetonitrile. The supernatant was analyzed for
both Icb and IVc by LC/MS/MS.
The stability of Icb was also evaluated, as described above, in Tris-HCl buffer
(0.1M,pH7.5).
(2) Hydrolysis of Icb in the Presence of Human Placenta! ALP
Solid human placental ALP was obtained from Sigma (P-3895, St. Louis,
MO). A solution of 1000 units/L was prepared in Tris-HCl buffer (0.1 M, pH 7.5).
Solutions of 100 and 10 units/L were obtained by serial dilution. Icb was incubated
in the 10, 100 and 1000 units/L solutions (n - 2) at 37°C for 2 hr. The starting
concentration of Icb in the incubation was 10 pM. Aliquots of 100 [iL samples were
taken at pre-determined times and added into K^EDTA microtainers followed by the
addition of 200 nJL of acetonitrile. The supernatant was analyzed for both Icb and
IVc by LC/MS/MS.
(1) In Vivo Studies in the Rat
Male Sprague-Dawley rats (300-350 g, Hilltop Lab Animals, Inc., Scottsdale,
PA) with cannulas implanted in the jugular vein were used. The rats were fasted
overnight in the PO pharmacokinetic studies. Blood samples were collected from the
jugular vein.
In the IV study, Icb was delivered at 1.4 mg/kg (free acid, or 1.1 mg/kg of IVc
equivalent) as a bolus over 0.5 min (n = 3). The concentration of the dosing solution
was 1.4 mg/mL, and the dosing volume was 1 mL/kg. Serial blood samples were
collected before dosing and at 2, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after
dosing.
In the PO study, Icb was administered at 6.9 mg/kg (free acid, or 5.6 mg/kg of
IVc equivalent) by oral gavage (n = 3). The concentration of the dosing solution was
1.4 mg/mL, and the dosing volume was 5 mL/kg. Serial blood samples were
collected before dosing and at 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
(2) In Vivo Studies in the Dog
The IV and PO studies of Icb were conducted in a crossover fashion in three
male beagle dogs (12 + 2.8 kg, Marshall Farms USA Inc., North Rose, NY). There
was a two-week washout period between the IV and PO studies.
Iti the IV study, Icb was infused via the cephalic vein at 1.3 rng/kg (free acid,
or 1.0 mg/lcg of IVc equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.6 mg/mL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
In the PO study, the dogs were fasted overnight before dosing. Icb was
administered by oral gavage at 6.0 mg/kg (free acid, or 4.9 mg/kg of FVc equivalent).
The concentration of the dosing solution was 12 mg/mL, and the dosing volume was
0.5 mL/kg. Serial blood samples were collected before dosing and at 15, 30,45 min,
1, 2, 4, 6, 8 and 24 hr after dosing.
(3) In Vivo Studies in the Monkey
The W and PO studies of Icb were conducted in a crossover fashion in three
male cynomolgus monkeys (10 + 1.6 kg, Charles River Biomedical Research
Foundation, Houston, TX). There was a two-week washout period between the IV
and PO studies.
hi the IV study, Icb was infused via the femoral vein at 1.4 mg/kg (free acid,
or 1.1 mg/kg of IVc equivalent) over 5 min at a constant rate of 0.1 mL/kg/min. The
concentration of the dosing solution was 2.8 mg/mL, and the dosing volume was 0.5
mL/kg. Serial blood samples were collected from the femoral artery before dosing
and at 5, 10, 15, 30, 45 min, 1, 2, 4, 6, 8 and 24 hr after dosing.
hi the PO study, the monkeys were fasted overnight before dosing. Icb was
administered by oral gavage at 4.9 mg/kg (free acid, or 4.0 mg/kg of IVc equivalent).
The concentration of the dosing solution was 9.8 mg/mL, and the dosing volume was
0.5 mL/kg. Serial blood samples were collected before dosing and at 15, 30, 45 min,
1, 2, 4, 6, 8 and 24 hr after dosing.
(4) Data Analysis
All results are expressed as mean + SD, unless specified otherwise.
The pharmacokinetic parameters of Icb and IVc were calculated by Non-
Compartmental Analysis using the KINETICA™ software program (version 4.0.2,
. InnaPhase Co., Philadelphia, PA). The Cmax and Tmax values were recorded
directly from experimental observations. The AUCo-n and AUCtot values were
calculated using the mixed log-linear trapezoidal summations. The total body
clearance (Cl), mean residence time (MRT), and the steady state volume of
distribution (Vss) were also calculated after intravenous administration. The absolute
oral bioavailability (expressed as %) was estimated by taking the ratio of dosenormalized
AUC values after oral doses to those after intravenous doses.
The in vitro intrinsic clearance of Icb in hepatocytes (Cl;nt) was calculated as
follows:
Clint (|iL/min/million cells) = Rate / CE
where Rate is the rate of metabolism in hepatocytes (pmol/min/million cells), and CE
is the concentration of Icb in the incubation.
The in vivo intrinsic hepatic clearance of Icb (Cl^in vivo) was calculated as follows:
120 (million cells) % g liver 1
munvnov t./ g hver kg body weight 1rv1A0A00
where % is 40, 32, 30 and 26 g liver/leg body weight for the rat, dog, monkey and
human, respectively (Davis and Morris, 1993).
The hepatic clearance Cljj was calculated from the following equation using the wellstirred
model:
.
C1H (mL/min/kg) = nj n
where Qh is the liver blood flow of 55,31, 44 and 21 mL/min/kg for the rat, dog,
monkey and human, respectively (Davis and Morris, 1993).
The hepatic extraction ration (ER) was calculated at follows:
ER = ClH/Qh
/wStudent's t-test was used for statistical analysis (Microsoft Excel, Redmond, WA).
Differences were considered statistically significant at the level of P In Vitro Studies
Stability of Icb in EDTA Blood, Serum and Tris-HCl Buffer
As part of the analytical assay validation, the stability of Icb was studied in
blood containing EDTA, which is known to be an inhibitor of alkaline phosphatases
(Bowers, Jr. and McComb, 1966; Yora and Sakagishi, 1986). After incubation at
37°C for 90 min, there was less than 2% conversion of Icb to IVc in blood containing
EDTA and in the presence of Tris-HCl buffer (Tables 39 and 40). Under the sample
storage condition of -20°C, the above small percentages of conversion observed at
37°C are not expected to introduce any significant ex vivo conversion during the
analysis of Icb.
(Table Removed)
To investigate the hydrolysis of Icb in the systemic circulation, Icb was
incubated in fresh serum (rat, dog, monkey and human) at 37°C for 90 min. The rate
of hydrolysis was, most rapid in the monkey serum, followed by rat, human and dog
sera (Table 41). The conversion of Icb to IVc was near stoichiometric.
Serum contains lower ALP activities as compared to tissues (McComb et al,
1979a). In addition, serum also contains ALP isoforms from tissue sources such as
bone, liver and intestine, as a result of enzyme leakage through the blood vessels
(Moss, 1983). Therefore, the hydrolysis of Icb in serum was probably mediated by
multiple isoforms of ALP.
(Table Removed)
To study the hydrolysis oflcb in a purified form, of human ALP, Icb was
incubated at 37°C (2 hr) with solutions containing human placental ALP (10, 100 and
1000 units/L). The disappearance t]/2 oflcb was determined (Table 42). As
expected, the rate of hydrolysis was faster in the solutions with, higher ALP activities.
We was also formed accordingly (Fig. 20). This indicates that Icb is hydrolyzed by
the ALP derived from humans to form IVc.
(Table Removed)
The pharmacokinetic parameters oflcb and IVc in rats after IV and oral
administration oflcb are summarized in Table 43. The plasma concentration versus
time profiles are shown in Figure 21. For comparison, the historical data from the
pharmacokinetic studies of IVc in rats are also shown.
The total body clearance (Cl) oflcb following IV administration was 49
mL/min/kg, suggesting that Icb is a high clearance compound in rats. The
elimination half-life (ti/2) and mean residence time (MRT) after TV administration
were 0.084 hr and 0.072 In; respectively. The volume of distribution oflcb at steady
state (Vss) was 0.21 L/lcg, suggesting very limited tissue distribution. The formation
of We from Icb after IV administration was rapid; IVc was detected at the first
sampling time point of 2 min (data not shown). The IV AUC ratio of IVc formed
from Icb vs. from the historical. IVc study was 1.0 (theoretical value for complete
conversion =1), suggesting complete conversion of Icb to IVc.
Icb was not detected (LLQ = 5 nM) in any plasma samples after oral
administration. The Tmax of We after oral administration of Icb was 0.80 lir, which
is shorter than the historical Tmax of We of 4.0 hr, indicating more rapid absorption
of IVc following the oral administration of the prodrag. The more rapid absorption of
We from the prodrag is likely the result of better aqueous solubility of Icb as well as
rapid hydrolysis of Icb to form We in the intestine. The absolute oral bioavailability
of We from Icb was 80%, similar to the historical We value of 82% (Table 43).
Moreover, the exposure of IVc from the Icb rat oral dose escalation study was
superior as compared to the historical data with IVc (Table 37 and Fig. 18).
The terminal plasma concentration vs. time profiles of IVc formed from Icb
are similar to the historical IVc profiles (Fig, 21).
(Table Removed)
The pharmacokinetic parameters of Icb and IVc in dogs after IV and oral
administration of Icb are summarized in Table 44. The plasma concentration versus
time profiles are shown in Figure 22. For comparison, the historical data from the
pharmacokinetic studies of IVc in dogs are also shown.
The Cl of Icb after IV administration was 64 mL/min/kg, significantly higher
than the liver blood flow of 31 mL/min/kg in dogs, and suggests the involvement of
extrahepatic hydrolysis and/or other route(s) of elimination (e.g., renal excretion).
The ti/2 and MRT after IV administration were 0.25 hr and 0.14 hr, respectively. Icb
was not detected beyond 2 hr. The Vss of Icb was 0.50 L/kg, suggesting low
potential for tissue distribution. The formation of IVc from Icb after IV
administration was rapid; IVc was detected at the first sampling time point of 5 min
(data not shown). The IV AUC ratio of We formed from Icb vs. from the historical
We study was 0.67, suggesting moderate conversion of Icb to IVc in dogs after IV
administration.
Icb was not detected (LLQ = 5 nM) in any plasma samples oral
administration. The Tmax of IVc after oral administration of Icb was 0.58 hr, which
is shorter than the historical Tmax of IVc of 1.3 hr, indicating more rapid absorption
of IVc following the oral administration of the prodrug. The absolute oral
bioavallability of IVc from Icb was 104%, similar to the Mstorical'IVc data of 89%.
Moreover, the exposure of IVc from the Icb dog tolerability study (dose escalation)
was better when compared to the historical data with IVc (Table 41 and Fig. 21).
The terminal plasma concentration vs. time profiles of IVc formed from Icb
are similar to the historical IVc profiles (Fig. 22).
(Table Removed)
The pharmacokinetic parameters of Icb and IVc in monkeys following IV and
oral administration of Icb are summarized in Table 45. The plasma concentration
versus time profiles are shown in Figure 23. For comparison, the historical data from
the pharmacokinetic studies of IVc in monkeys are also shown.
The Cl of Icb after IV administration was 47 mL/min/kg, similar to the liver
blood flow of 44 mL/min/kg in monkeys, suggesting that Icb is a high clearance
compound in monkeys. The t\/2 and MRT after IV administration were O.OS9hr and
0.097 hr, respectively. The Vss of Icb was 0.27 L/kg, suggesting limited tissue
distribution. The formation of IVc from Icb after IV administration was rapid; IVc
was detected at the first sampling time point of 5 min (data not shown). The IV AUC
ratio of IVc formed from Icb vs. from the historical IVc study was 0.90, suggesting
good conversion of Icb to IVc.
Icb was not detected (LLQ = 5 nM) in any plasma samples after oral
administration. The Tmax of IVc after oral administration of Icb was 0.92 hr, which
is shorter than the historical Tmax of IVc of 2.3 hr, indicating more rapid absorption
of IVc following the oral administration of the prodrag. The absolute oral
bioavailability of IVc from Icb was 122%, which is higher that the historical IVc data
of 64% (Table 45).
The terminal plasma concentration vs. time profiles of IVc formed from Icb
are similar to the historical IVc profiles (Fig. 23).
(Table Removed)
Additional Studies with Prodrug le
Prodrug le was dosed orally to rats using methodology similar to that
described above for the other prodrugs. Following PO dosing, parent molecule IVe
was detected in the plasma.
Additional profiling Section 5:
Additional Studies with prodrug If
Prodrug If was dosed orally to rats using methodology similar to that
described above for the other prodrugs. Following PO dosing, parent molecule IVf
was detected in the plasma.
The following Table 47 shows the data contained from oral dosing studies in rats as
described in additional profiling sections 4 and 5.
(Table Removed)
Note on detection of prodrugs in plasma and other tissues. Once a salt form of a
prodrug is administered, it is understood that in the body, scrambling of the salt may
occur. However the assays used to quantitate for prodrugs in the subject animal
models deletes by analysis the free acid ofthephophate. This analyzing for example
a lysine salt lab or a free acid lac is assumed to be analyzing for the same species
and is not intended to imply that the species detected was actually the lysine salt. In
this application, this convention applies to samples obtained from in vivo studies and
samples only
Biology
• "(iM" means micromolar;
• "mL" means milliliter;
• "jil" means microliter;
• "mg" means milligram;
• "DMSO" means dimethylsulfoxide
The materials and experimental procedures used to assess the anti-HIV
activity of the parent compounds which are generated from the prodrugs in vivo are
described below:
Cells:
• The human T cell line MT-2 and PM1 (AIDS Research and Reference Reagent
Program, National Institutes of Health) were maintained and propagated in
Medium RPMI-1640 (Invitrogen, Carlsbad, CA), containing 10% fetal Bovine
serum. (FBS, Sigma, St. Louis , MO).
Virus:
• Laboratory strains ofHW-1 -the T-tropic strain LAI was obtained through the
AIDS Research and Reference Reagent Program, National Institutes of Health. It
was amplified in MT-2 cells and titered using a virus yield assay (2). Detection
was achieved through use of a reverse transcriptase assay (3), adapted for use with
a Scintillation Proximity detection protocol (1) (Amersham Biosciences,
Piscataway, NJ).
Experiment
1. Compounds stocks were prepared by dissolving in DMSO to 30 mM. For
polypropylene plates, so that the concentrations were 100-fold greater than the
final assay concentration. For antiviral and cytotoxicity assays, 2 ul was added
per well (1% final DMSO concentration).
2. Compounds were added from dilution plates to 96 well tissue culture plates,
containing 100 ul Medium RPMI-1640, containing 10 % fetal bovine serum at a
concentration of 20 µM.
3. For antiviral assays, cells were infected at a multiplicity of infection of 0.005.
After 1 h at 37 °C, infected cells were diluted to 200,000 cells per ml in Medium
RPMI-1640, containing 10% fetal bovine serum. 100 ul of this solution was
added per well, giving a final volume of 200 pi.
4. Plates were incubated at 37 °C in a humidified COa incubator and harvested after
5 days.
5. Viral infections were monitored by measuring reverse transcriptase activity in the
supernatants of infected wells as described above. The percent inhibition for each
compound was calculated by quantifying the readout level in cells infected in the
presence of each compound as a percentage of that observed for cells infected in
the absence of compound and subtracting such a determined value from 100.
6. An ECso provides a method for comparing the antiviral potency of the compounds
of this invention. The effective concentration for fifty percent inhibition (ECso)
was calculated with the Microsoft Excel Xlfit curve fitting software. For each
compound, curves were generated from percent inhibition calculated at 8 different
concentrations by using a four paramenter logistic model (model 205). The
data for the compounds is shown in Table 48.
(Table Removed)
The anti-HIV activity of the prodrugs themselves are not relevant since the
parent molecules, as shown by the studies below, are generated from the prodrugs in
vivo and are the active ingredient and also the major species in the plasma. In
addition, the prodrugs may slowly convert to parents in the in vitro assays at least to a
limited extent thus complicating interpretation of the antiviral data.
Cytotoxicity
1. Cytotoxicity assays were conducted with the same MT-2 cells, using methodology
well known in the art. This method has been described in the literature (4). In
brief, cells were incubated in the presence of drag for six days, after which cell
viability was measured using a redox-active dye reduction assay. 50 ul of XTT
reagent (1 mg/ml 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-
carboxanilide, 10 ug/ml phenazine methosulfate dissolved in phosphate buffered
saline) was added to each well and incubated for 3 hours. Color formation by
actively respiring cells was quantitated in a plate reader at 450 nm, and used to
determine a CC50. The CC50 for IVa,lVb, We, and IVd parent molecules were
greater than 10 jiM when measured by this method. The Cytotoxicity data is a
secondary screen which shows the compounds are not nonspecifically killing the
cells which were used in the antiviral assay and provides further support for the
contention that the compounds possess antiviral activity.
Thus, in accordance with the present invention there is further provided a
method of treating and a pharmaceutical composition for treating viral infections such
as HIV infection and AIDS. The treatment involves administering to a patient in
need of such treatment a pharmaceutical composition comprising a pharmaceutical
carrier and a therapeutically-effective amount of a compound of the present invention.
The pharmaceutical composition may be in the form of orally-admrnistrable
suspensions or tablets; nasal sprays, sterile injectable preparations, for example, as
sterile injectable aqueous or oleagenous suspensions or suppositories.
When administered orally as a suspension, these compositions are prepared
according to techniques well-known in the art of pharmaceutical formulation and may
contain microcrystalline cellulose for imparting bulk, alginic acid or sodium alginate
as a suspending agent, methylcellulose as a viscosity enhancer, and
sweetners/flavoring agents known in the art. As immediate release tablets, these
compositions may contain microcrystalline cellulose, dicalcium phosphate, starch,
magnesium stearate and lactose and/or other excipients, binders, extenders,
disintegrants, diluents and lubricants known in the art.
The injectable solutions or suspensions maybe formulated according to
known art, using suitable non-toxic, parenterally-acceptable diluents or solvents, such
as mannitol, 1,3-butanediol, water, Ringer's solution or isotonic sodium chloride
solution, or suitable dispersing or wetting and suspending agents, such as sterile,
bland, fixed oils, including synthetic mono- or diglycerides, and fatty acids, including
oleic acid.
The compounds of this invention can be administered orally to humans in a
dosage range of 1 to 100 mg/kg body weight in divided doses. One preferred dosage
range is 1 to 10 mg/kg body weight orally in divided doses. Other preferred dosage
ranges are 1 to 20 mg/kg and 1 to 30 mg/kg body weight orally in divided doses. It
will be understood, however, that the specific dose level and frequency of dosage for
any particular patient may be varied and will depend upon a variety of factors
including the activity of the specific compound employed, the metabolic stability and
length of action of that compound, the age, body weight, general health, sex, diet,
mode and time of administration, rate of excretion, drug combination, the severity of
the particular condition, and the host undergoing therapy.



We Claim:
1. A compound of Formula I,
(Formula Removed)
wherein:
X is C;
W is N with the proviso that when W is N, R2 does not exist;
V is C;
R1 is halogen;
R3 is 1,2,3-triazolyl attached at position N-l;
E is hydrogen or a pharmaceutically acceptable mono or bis salt thereof;
Y is
(Formula Removed)
R10, R11, R12, R13, R14, R15, R16, R17 are each H;
R18 is selected from the group consisting of C(0)-phenyl or quinazolyl.
2. A compound as claimed in claim 1, wherein:
R1 is F.
3. A compound of Formula I,
(Formula Removed)
wherein: X is C;
W is N with the proviso that when W is N, R does not exist;
V is C;
R1 is methoxy;
E is hydrogen or a pharmaceutically acceptable mono or bis salt thtereof;
Y is
(Formula Removed)
R3 is trazolyl wherein said triazolyl may be independently optionally substituted with C1-6
alkyl; and
R18 is quinazolyl, and R10, R11, R12, R13, R14, R15, R16, R17, are each H.
4. A process for preparing Compound Ic having the structure
(Formula Removed)
comprising:
(a) alkylating Compound IVc having the structure
(Formula Removed)
with 2.5 molar equivalents of di-tert butyl chioromethyl phosphate per mole of IVc having the structure Z
(Formula Removed)
in the presence of 2.5 molar equivalents of CS2CO3 as a base per mole of IVc, 2 molar equivalents of KI per mole of IVc, and 5-10 ml of N-methyl-pyrro-lidinone per gram of IVc, at a reaction temperature of about 25-30°C, to form a Compound IIC having the structure
(Structure Removed)
(b) deprotecting at a temperature of about 40°C. Compound IIc of both tert-butyl groups
in an excess of acetone and water; and
(c) recovering Compound Ic.
5. The compound l-benzolyl-4-[2-[4-methoxy-7-(3-methyl-lH-l,2,4-triazol-l-yl)-l-[(phosphonooxy)methyl]-lH-pyrrolo[2,3-c]pyridin3-yl]-l,2-dioxoethyl]-piperazine or a pharmaceutically acceptable salt thereof, having the following structure:
(Structure Removed)

Documents:

5335-DELNP-2006-Correspondence Others-(13-03-2012).pdf

5335-DELNP-2006-Form-3-(13-03-2012).pdf

5335-DELNP-2006-Petition-137-(13-03-2012).pdf

5355-DELNP-2006-Abstract-(23-03-2012).pdf

5355-delnp-2006-abstract.pdf

5355-delnp-2006-assignments.pdf

5355-DELNP-2006-Claims-(23-03-2012).pdf

5355-delnp-2006-claims.pdf

5355-DELNP-2006-Correspondence Others-(23-03-2012).pdf

5355-delnp-2006-correspondence-others.pdf

5355-DELNP-2006-Description (Complete)-(23-03-2012).pdf

5355-delnp-2006-description (complete).pdf

5355-DELNP-2006-Drawings-(23-03-2012).pdf

5355-delnp-2006-drawings.pdf

5355-DELNP-2006-Form-1-(23-03-2012).pdf

5355-delnp-2006-form-1.pdf

5355-DELNP-2006-Form-2-(23-03-2012).pdf

5355-delnp-2006-form-2.pdf

5355-delnp-2006-form-3.pdf

5355-delnp-2006-form-5.pdf

5355-DELNP-2006-GPA-(23-03-2012).pdf

5355-delnp-2006-gpa.pdf

5355-delnp-2006-Granted Claims-(15-09-2006).pdf

5355-delnp-2006-pct-210.pdf

5355-delnp-2006-pct-304.pdf

abstract.jpg


Patent Number 254948
Indian Patent Application Number 5355/DELNP/2006
PG Journal Number 02/2013
Publication Date 11-Jan-2013
Grant Date 07-Jan-2013
Date of Filing 15-Sep-2006
Name of Patentee BRISTOL-MYERS SQUIBB COMPANY.
Applicant Address P.O. BOX 4000, ROUTE 206 AND PROVINCE LINE ROAD, PRINCETON, NEW JERSEY 08543-4000, U.S.A.
Inventors:
# Inventor's Name Inventor's Address
1 YASUTSUGU UEDA 46 OLDE ORCHARD ROAD, CLINTON, CONNECTICUT 06413, USA.
2 TIMOTHY P. CONNOLLY 6 ELIZABETH ROAD, PORTLAND, CONNECTICUT 06480, USA.
3 JOHN F. KADOW 9 QUARRY RUN, WALLINGFORD, CONNECTICUT 06492, USA.
4 NICHOLAS A. MEANWELL 15 VALLI DRIVE EAST HAMPTON, CONNECTICUT 06424, USA.
5 TAO WANG 1312 TOWN BROOKE, MIDDLETOWN, CONNECTICUT 06457, USA.
6 CHUNG-PIN H. CHEN 92 JOSHUA TRAIL, MADISON, CONNECTICUT 06443, USA
7 KAP-SUN YEUNG 164 DORSET LANE, MADISON, CONNECTICUT 06443, USA
8 ZHONGXING ZHANG 14 MARTLESHAMHEATH LANE, MADISON, CONNECTICUT 06443, USA
9 DAVID KENNETH LEAHY 44 MUSTANG TRAIL, SOMERSET, NEW NERSEY 08873, USA
10 SHAWN K. PACK 1212 ASPEN DR. PLAINSBORO, NEW JERSEY 08536, USA
11 NACHIMUTHU SOUNDARARAJAN 10 TALIA ROAD, KENDALL PARK, NEW JERSEY 08824, USA
12 PIERRE SIRARD 117 DE ROUVILLE, ST. JEAN SUR RICHELIEU, QUEBEC J2W 1A5, CANADA.
13 KATHIA LEVESQUE 585 LEVEILLEE, STE-CATHERINE, QUEBEC J5C 1H2, CANADA
14 DOMINIQUE THORAVAL 2 AVENUE NAPLES, CANDIAC, QUEBEC J5R 5N3, CANADA.
PCT International Classification Number C07F 9/09
PCT International Application Number PCT/US2005/006980
PCT International Filing date 2005-03-03
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/635,231 2004-12-10 U.S.A.
2 60/553,320 2004-03-15 U.S.A.